A293938 - OEIS

A293938

Poincaré series for invariant polynomial functions on the space of binary forms of degree 13.

1, 0, 2, 0, 22, 33, 181, 375, 1120, 2342, 5467, 10668, 21660, 39562, 72816, 125484, 215161, 352424, 572086, 897867, 1394315, 2110350, 3159826, 4635480, 6731131, 9612072, 13595657, 18964299, 26221103, 35828058, 48562922, 65155439, 86777107, 114549589, 150198041, 195400674, 252651242

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OFFSET

0,3

COMMENTS

Many of these Poincaré series has every other term zero, in which case these zeros have been omitted.

LINKS

Table of n, a(n) for n=0..36.

Andries Brouwer, Poincaré Series (See n=13)

EXAMPLE

The Poincaré series is (1 + t^4 - t^6 + 19t^8 + 31t^10 + 157t^12 + 321t^14 + 885t^16 + 1756t^18 + 3794t^20 + 6856t^22 + 12788t^24 + 21324t^26 + 35633t^28 + 55326t^30 + 85174t^32 + 124064t^34 + 178645t^36 + 246238t^38 + 334814t^40 + 439321t^42 + 568305t^44 + 712862t^46 + 881834t^48 + 1061455t^50 + 1259989t^52 + 1459221t^54 + 1666984t^56 + 1860904t^58 + 2049854t^60 + 2209072t^62 + 2349306t^64 + 2446352t^66 + 2514111t^68 + 2530530t^70 + 2514111t^72 + 2446352t^74 + 2349306t^76 + 2209072t^78 + 2049854t^80 + 1860904t^82 + 1666984t^84 + 1459221t^86 + 1259989t^88 + 1061455t^90 + 881834t^92 + 712862t^94 + 568305t^96 + 439321t^98 + 334814t^100 + 246238t^102 + 178645t^104 + 124064t^106 + 85174t^108 + 55326t^110 + 35633t^112 + 21324t^114 + 12788t^116 + 6856t^118 + 3794t^120 + 1756t^122 + 885t^124 + 321t^126 + 157t^128 + 31t^130 + 19t^132 - t^134 + t^136 + t^140)/ (1 - t^4)(1 - t^6)(1 - t^8)(1 - t^10)(1 - t^12)(1 - t^14)(1 - t^16)(1 - t^18)(1 - t^20)(1 - t^22)(1 - t^24)

MAPLE

nmax := 120 :

(1 + t^4 - t^6 + 19*t^8 + 31*t^10 + 157*t^12 + 321*t^14 + 885*t^16 + 1756*t^18 + 3794*t^20 + 6856*t^22 + 12788*t^24 + 21324*t^26 + 35633*t^28 + 55326*t^30 + 85174*t^32 + 124064*t^34 + 178645*t^36 + 246238*t^38 + 334814*t^40 + 439321*t^42 + 568305*t^44 + 712862*t^46 + 881834*t^48 + 1061455*t^50 + 1259989*t^52 + 1459221*t^54 + 1666984*t^56 + 1860904*t^58 + 2049854*t^60 + 2209072*t^62 + 2349306*t^64 + 2446352*t^66 + 2514111*t^68 + 2530530*t^70 + 2514111*t^72 + 2446352*t^74 + 2349306*t^76 + 2209072*t^78 + 2049854*t^80 + 1860904*t^82 + 1666984*t^84 + 1459221*t^86 + 1259989*t^88 + 1061455*t^90 + 881834*t^92 + 712862*t^94 + 568305*t^96 + 439321*t^98 + 334814*t^100 + 246238*t^102 + 178645*t^104 + 124064*t^106 + 85174*t^108 + 55326*t^110 + 35633*t^112 + 21324*t^114 + 12788*t^116 + 6856*t^118 + 3794*t^120 + 1756*t^122 + 885*t^124 + 321*t^126 + 157*t^128 + 31*t^130 + 19*t^132 - t^134 + t^136 + t^140)/ (1 - t^4)/(1 - t^6)/(1 - t^8)/(1 - t^10)/(1 - t^12)/(1 - t^14)/(1 - t^16)/(1 - t^18)/(1 - t^20)/(1 - t^22)/(1 - t^24) ;

taylor(%, t=0, nmax) ;

gfun[seriestolist](%) ;

seq( %[1+2*i], i=0..nmax/2-1) ; # R. J. Mathar, Oct 26 2017

CROSSREFS

For these Poincaré series for d = 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 20, 24 see A097852, A293933, A097851, A293934, A293935, A293936, A293937, A293938, A293939, A293940, A293941, A293942, A293943 respectively.

Sequence in context: A256303 A156438 A282134 * A254042 A368014 A009378

Adjacent sequences: A293935 A293936 A293937 * A293939 A293940 A293941

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Oct 20 2017

STATUS

approved