A340809 Decimal expansion of Product_{primes p == 4 (mod 5)} 1/(1-p^(-4)).

1, 0, 0, 0, 0, 0, 9, 2, 2, 6, 1, 5, 8, 1, 0, 2, 5, 7, 5, 1, 4, 1, 6, 8, 8, 0, 4, 1, 4, 3, 8, 4, 7, 1, 5, 4, 7, 5, 1, 1, 0, 1, 0, 4, 0, 4, 7, 9, 5, 3, 7, 1, 9, 6, 9, 8, 8, 5, 0, 4, 3, 5, 5, 0, 0, 7, 5, 8, 3, 4, 2, 2, 9, 7, 8, 6, 8, 4, 8, 4, 7, 9, 5, 5, 1, 5, 3, 2, 0, 9, 8, 4, 2, 4, 8, 7, 4, 4, 6, 6, 5, 2, 9, 9, 6

Offset: 1

Author

R. J. Mathar, Jan 22 2021

Keywords

• nonn
• cons

Comments

Equals also the same product over the primes p==9 (mod 10).

Examples

			1.0000092261581025751416880414384715475110104...
		

Links

• Vaclav Kotesovec, Table of n, a(n) for n = 1..500
• R. J. Mathar, Table of Dirichlet L-series and prime zeta modulo functions for small moduli, arXiv:1008.2547 [math.NT], 2010-2015, Zeta_{m=5,n=4}(s=4).

Crossrefs

Cf. A004618, A030433, A340127 (s=2), A340628, A340808, A340926, A340927.

Formula

Equals A340127 ^2/A340628

Equals Sum_{k>=1} 1/A004618(k)^4. - Amiram Eldar, Jan 24 2021

Extensions

More digits from Vaclav Kotesovec, Jan 22 2021