A329491 Dirichlet g.f.: Sum_{n>=0} a(n+1)/(1+10n)^s = Product ((1+p^(-s))/(1-p^(-s))) (p==1 mod 5).

1, 2, 0, 2, 2, 0, 2, 2, 0, 0, 2, 0, 2, 2, 0, 2, 0, 0, 2, 2, 0, 2, 0, 0, 2, 2, 0, 2, 2, 0, 0, 2, 0, 2, 4, 0, 0, 0, 0, 0, 2, 0, 2, 2, 0, 4, 2, 0, 0, 2, 0, 0, 2, 0, 2, 0, 0, 2, 0, 0, 2, 0, 0, 2, 2, 0, 2, 4, 0, 2, 2, 0, 0, 0, 0, 2, 2, 0, 4, 0, 0, 2, 2, 0, 0

Offset

1,2

Comments

If the D.g.f. is squared we get A031362.

Links

Table of n, a(n) for n=1..85.

Prog

(PARI)
t4=direuler(p=2, M, (1+(p%5<2)*X)) \\ p == 0 or 1 mod 5
t5=direuler(p=2, M, 1/(1+(p%5<1)*X)) \\ p == 0  mod 5
t6=dirmul(t4, t5) \\ p == 1 mod 5
t7=direuler(p=2, M, 1/(1-(p%5<2)*X))
t8=direuler(p=2, M, (1-(p%5<1)*X))
t9=dirmul(t7, t8)
t10=dirmul(t6, t9)
t11=vector(100, n, t10[10*n+1]) \\ (and then prepend 1)

Crossrefs

Cf. A031362.

Sequence in context: A123530 A161516 A347730 * A123063 A031358 A279103

Adjacent sequences: A329488 A329489 A329490 * A329492 A329493 A329494

Keyword

nonn

Author

N. J. A. Sloane, Nov 15 2019

Status

approved