A032288 "DIK" (bracelet, indistinct, unlabeled) transform of 1,3,5,7...

1, 4, 9, 22, 46, 109, 237, 571, 1362, 3459, 8881, 23698, 63846, 175489, 485941, 1359240, 3821170, 10803787, 30654681, 87295726, 249262766, 713583861, 2047210813, 5885081941, 16947632202, 48885431563, 141220349049

Offset

1,2

Links

Andrew Howroyd, Table of n, a(n) for n = 1..200

C. G. Bower, Transforms (2)

Index entries for sequences related to bracelets

Prog

(PARI) seq(n)={Vec(x*(1 + 2*x - x^2 + 2*x^3 + 2*x^4 + 2*x^5)/((1 - x)^2*(1 - 3*x^2)) + sum(d=1, n, eulerphi(d)/d*log((1-x^d)^2/(1-3*x^d) + O(x*x^n))))/2} \\ Andrew Howroyd, Jun 20 2018

Crossrefs

Sequence in context: A200155 A002835 A253289 * A336975 A076859 A042833

Adjacent sequences: A032285 A032286 A032287 * A032289 A032290 A032291

Keyword

nonn

Author

Christian G. Bower

Status

approved