A340315 Decimal expansion of sum of reciprocals of A000111(n) (where A000111(n) is the n-th Euler or up/down number).

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

Offset

1,1

Comments

The series 1/1 + 1/1 + 1/1 + 1/2 + 1/5 + 1/16 + 1/61 + 1/272 + 1/1385 + 1/7936 + ... converges to 3.783440983500797666683...

Links

Table of n, a(n) for n=1..104.

Formula

Equals Sum_{k>=0} 1/A000111(k).

Example

3.783440983500797666683...

Prog

(PARI) f(n)=if(n, 2*abs(polylog(-n, I)), 1); \\ A000111
suminf(n=0, 1/f(n)) \\ Michel Marcus, Jan 04 2021

Crossrefs

Cf. A000111, A001250, A173253.

Sequence in context: A064208 A078004 A197728 * A267501 A016667 A006834

Adjacent sequences: A340312 A340313 A340314 * A340316 A340317 A340318

Keyword

nonn,cons

Author

Marco Ripà, Jan 04 2021

Extensions

More digits from Alois P. Heinz, Jan 06 2021

Status

approved