A383819 Decimal expansion of -Sum_{k>=1} mu(3*k)/(27^k + 1), where mu is the Möbius function.

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

Offset: 0

Author

Artur Jasinski, May 16 2025

Keywords

• nonn
• cons

Examples

			0.034344352913278175288827529...
		

Crossrefs

Cf. A008683, A383817, A383820.

Programs

Mathematica

Join[{0}, RealDigits[NSum[1/3^(3^k) - 2/3^(2*3^k), {k, 1, Infinity}, WorkingPrecision -> 120]][[1]]] (* Amiram Eldar, May 16 2025 *)

PARI

-sum(k=1,logint(2^getlocalbitprec(),3)+1,moebius(3*k)/(27.^k + 1),0.) \\ Bill Allombert

Formula

Equals Sum_{k>=1} (1/3^(3^k) - 2/3^(2*3^k)). - Amiram Eldar, May 16 2025