The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A015165

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A015165

Theta series of 17-dimensional lattice Q'_17(6)^{+6}.
(history; published version)

#25 by N. J. A. Sloane at Fri Dec 07 12:31:04 EST 2018

STATUS

proposed

approved

#24 by Michel Marcus at Thu Nov 29 01:24:51 EST 2018

STATUS

editing

proposed

#23 by Michel Marcus at Thu Nov 29 01:24:47 EST 2018

LINKS

Gheorghe Coserea, <a href="/A015165/a015165.txt">Gram matrix</a>.

STATUS

proposed

editing

#22 by Andrew Howroyd at Wed Nov 28 23:53:32 EST 2018

STATUS

editing

proposed

#21 by Andrew Howroyd at Wed Nov 28 23:46:43 EST 2018

PROG

(PARI)

GramMatrix()={my(p=[11, 2, 2, -4, -4, -7, -1, 2, 5, 5, 2, -1, -7, -4, -4, 2, 2]); matrix(#p, #p, i, j, p[(i-j) %#p + 1])}

a(n)={if(n==0, 1, 2*qfrep(GramMatrix(), n, 0)[n])} \\ Andrew Howroyd, Nov 29 2018

CROSSREFS

Cf. A015158, A015159, A015160, A015161, A015162, A015163, A015164.

STATUS

proposed

editing

Discussion

Wed Nov 28

23:53

Andrew Howroyd: I really think a 2nd PARI version that is self contained and works in browser/windows is also worth adding.

#20 by Gheorghe Coserea at Wed Nov 28 19:54:45 EST 2018

STATUS

editing

proposed

#19 by Gheorghe Coserea at Wed Nov 28 19:53:17 EST 2018

PROG

(PARI) \\ system("wget https://oeis.org/A015165/a015165.txt");

g = matconcat(read("a015165.txt")~);

seq(N, g, flag=0) = concat(1, 2*Vec(qfrep(g, N, flag)));

seq(33, g) \\ Gheorghe Coserea, Nov 28 2018

#18 by Gheorghe Coserea at Wed Nov 28 19:50:47 EST 2018

LINKS

Gheorghe Coserea, <a href="/A015165/a015165.txt">Gram matrix</a>.

CROSSREFS

Cf. A015158.

STATUS

proposed

editing

#17 by Gheorghe Coserea at Wed Nov 28 07:43:04 EST 2018

STATUS

editing

proposed

Discussion

Wed Nov 28

07:53

Gheorghe Coserea: I have looked to see if PARI has a way to build a circulant matrices out of a vector (similar to Matlab T = toeplitz(c,r) or T = toeplitz(r) constructions) and found nothing ... not a big deal but having it helps with clean code

#16 by Gheorghe Coserea at Wed Nov 28 07:42:54 EST 2018

EXTENSIONS

More terms from Gheorghe Coserea, Nov 28 2018

STATUS

proposed

editing