A100649 a(n) is the numerator of 1 - Sum_{i=1..n} Bernoulli(i).

1, 3, 4, 4, 41, 41, 47, 47, 289, 289, 1502, 1502, 15551, 15551, 5809, 5809, 3818123, 3818123, -76776508, -76776508, 934336415, 934336415, -127396984577, -127396984577, 6013822435553, 6013822435553, -149990624319638, -149990624319638, 167911724519886437, 167911724519886437

Offset

0,2

Links

Table of n, a(n) for n=0..29.

Example

1, 3/2, 4/3, 4/3, 41/30, 41/30, 47/35, 47/35, 289/210, 289/210, 1502/1155, 1502/1155, 15551/10010, 15551/10010, 5809/15015, 5809/15015, 3818123/510510, 3818123/510510, ...

Maple

A100649 := proc(n) 1-add( bernoulli(i), i=1..n) ; numer(%) ; end proc: # R. J. Mathar, Jul 01 2011

Mathematica

a[n_]:=Numerator[1-Sum[BernoulliB[i], {i, n}]]; Array[a, 30, 0] (* Stefano Spezia, Aug 25 2025 *)

Crossrefs

Cf. A027641, A027642, A100650 (denominators).

Sequence in context: A023189 A067137 A060115 * A158962 A263824 A215747

Adjacent sequences: A100646 A100647 A100648 * A100650 A100651 A100652

Keyword

sign,frac

Author

N. J. A. Sloane, Dec 05 2004

Status

approved