A032251 "DHK" (bracelet, identity, unlabeled) transform of 2,2,2,2,...

1, 2, 3, 6, 9, 18, 45, 118, 336, 954, 2695, 7590, 21321, 59890, 168273, 473966, 1337476, 3785154, 10738373, 30546502, 87099571, 248937978, 712995733, 2046236598, 5883318437, 16944709370, 48880145967, 141211579446

Offset

0,2

Links

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

C. G. Bower, Transforms (2)

Prog

(PARI)
DHK(p, n)={my(q=((1+p)^2/(1-subst(p, x, x^2))-1)/2); p + (p^2-subst(p, x, x^2))/2 + sum(d=1, n, moebius(d)*(log(subst(1/(1+O(x*x^(n\d))-p), x, x^d))/d - subst(q + O(x*x^(n\d)), x, x^d)))/2}
seq(n)={Vec(1 + DHK(2*x/(1-x) + O(x*x^n), n))} \\ Andrew Howroyd, Sep 21 2018

Crossrefs

Sequence in context: A018582 A018619 A018638 * A018679 A018741 A161704

Adjacent sequences: A032248 A032249 A032250 * A032252 A032253 A032254

Keyword

nonn

Author

Christian G. Bower

Extensions

a(0)=1 prepended by Andrew Howroyd, Sep 21 2018

Status

approved