A285013 Number of periodic palindromic structures of length n using an infinite alphabet.

1, 1, 2, 2, 5, 5, 13, 15, 41, 52, 144, 203, 578, 877, 2605, 4140, 12869, 21147, 69178, 115975, 398766, 678570, 2450406, 4213597, 15939952, 27644437, 109304914, 190899322, 787016238, 1382958545, 5931824093, 10480142147, 46673259309, 82864869804, 382473282504

Offset

0,3

Comments

See A285012 for additional information. Permuting the symbols will not change the structure.

Links

Andrew Howroyd, Table of n, a(n) for n = 0..500

Prog

(PARI) \\ Requires T from A285012.
seq(n)={my(A=T(n)); concat([1], vector(n, i, vecsum(A[i, ])))} \\ Andrew Howroyd, Oct 02 2019

Crossrefs

Row sums of A285012.

Cf. A165137, A284841, A285042.

Sequence in context: A056505 A056506 A056507 * A095014 A129996 A208355

Adjacent sequences: A285010 A285011 A285012 * A285014 A285015 A285016

Keyword

nonn

Author

Andrew Howroyd, Apr 07 2017

Extensions

a(0)=1 prepended and terms a(28) and beyond from Andrew Howroyd, Oct 02 2019

Status

approved