A156846 - OEIS

A156846

a(n) = 12167n - 3588.

8579, 20746, 32913, 45080, 57247, 69414, 81581, 93748, 105915, 118082, 130249, 142416, 154583, 166750, 178917, 191084, 203251, 215418, 227585, 239752, 251919, 264086, 276253, 288420, 300587, 312754, 324921, 337088, 349255, 361422, 373589

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OFFSET

1,1

COMMENTS

The identity (279841*n^2-165048*n+24335)^2-(529*n^2-312*n+46)*(12167*n-3588)^2=1 can be written as A156843(n)^2-A156841(n)*a(n)^2=1.

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..10000

Index entries for linear recurrences with constant coefficients, signature (2,-1).

FORMULA

a(n) = 2*a(n-1) -a(n-2).

G.f.: x*(8579+3588*x)/(x-1)^2.

MATHEMATICA

LinearRecurrence[{2, -1}, {8579, 20746}, 40]

PROG

(Magma) I:=[8579, 20746]; [n le 2 select I[n] else 2*Self(n-1)-Self(n-2): n in [1..50]];

(PARI) a(n)=12167*n-3588 \\ Charles R Greathouse IV, Dec 23 2011

CROSSREFS

Cf. A156841, A156843, A156849.

Sequence in context: A217163 A243839 A287119 * A324711 A221053 A370972

Adjacent sequences: A156843 A156844 A156845 * A156847 A156848 A156849

KEYWORD

nonn,easy

AUTHOR

Vincenzo Librandi, Feb 17 2009

STATUS

approved