login
Shifts 9 places left under Euler transform with a(0)=0 and a(n)=1 for n<9.
3

%I #13 May 08 2019 22:17:59

%S 0,1,1,1,1,1,1,1,1,1,1,2,3,5,7,11,15,22,30,42,57,80,109,152,211,296,

%T 415,588,832,1185,1689,2413,3449,4940,7073,10141,14544,20880,29991,

%U 43131,62064,89417,128925,186090,268808,388677,562381,814393,1180070,1711131

%N Shifts 9 places left under Euler transform with a(0)=0 and a(n)=1 for n<9.

%H Alois P. Heinz, <a href="/A218026/b218026.txt">Table of n, a(n) for n = 0..1000</a>

%H N. J. A. Sloane, <a href="/transforms.txt">Transforms</a>

%F G.f.: x + x^2 + x^3 + x^4 + x^5 + x^6 + x^7 + x^8 + x^9 / Product_{n>=1} (1 - x^n)^a(n). - _Ilya Gutkovskiy_, May 08 2019

%p with(numtheory):

%p b:= proc(n) option remember; `if`(n=0, 1,

%p (add(add(d*a(d), d=divisors(j)) *b(n-j), j=1..n))/n)

%p end:

%p a:= n-> `if`(n<9, signum(n), b(n-9)):

%p seq(a(n), n=0..60);

%Y Column k=9 of A144018.

%Y Cf. A316081.

%K nonn,eigen

%O 0,12

%A _Alois P. Heinz_, Oct 18 2012