A032286 "DIK" (bracelet, indistinct, unlabeled) transform of 5,5,5,5...

5, 20, 65, 240, 957, 4360, 21075, 107760, 566375, 3039903, 16529655, 90798535, 502567665, 2799313350, 15674233045, 88163236380, 497851322925, 2821131185200, 16035833020335, 91404088484949, 522308650924665, 2991403124124120, 17168050141237515, 98716282462085185

Offset

1,1

Links

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

C. G. Bower, Transforms (2)

Index entries for sequences related to bracelets

Formula

G.f.: (5*x*(1+3*x+x^2)/((1-x)*(1-6*x^2)) + Sum_{d>0} phi(d)*log((1-x^d)/(1-6*x^d))/d)/2. - Andrew Howroyd, Jun 20 2018

Prog

(PARI) seq(n)={Vec(5*x*(1+3*x+x^2)/((1-x)*(1-6*x^2)) + sum(d=1, n, eulerphi(d)/d*log((1-x^d)/(1-6*x^d) + O(x*x^n))))/2} \\ Andrew Howroyd, Jun 20 2018

Crossrefs

Cf. A032283.

Sequence in context: A120297 A271066 A271599 * A097552 A322600 A084850

Adjacent sequences: A032283 A032284 A032285 * A032287 A032288 A032289

Keyword

nonn

Author

Christian G. Bower

Extensions

Terms a(21) and beyond from Andrew Howroyd, Jun 20 2018

Status

approved