%I #18 Feb 15 2021 15:43:42
%S 1,2,3,3,30,30,35,35,210,210,1155,1155,10010,10010,15015,15015,510510,
%T 510510,1616615,1616615,1939938,1939938,22309287,22309287,74364290,
%U 74364290,111546435,111546435,6469693230,6469693230,33426748355,33426748355,200560490130,200560490130
%N Denominator of 1 - Sum_{i=1..n} Bernoulli(i).
%H Amiram Eldar, <a href="/A100650/b100650.txt">Table of n, a(n) for n = 0..2369</a>
%e 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, ... = A100649/A100650.
%p A100650 := proc(n) 1-add( bernoulli(i),i=1..n) ; denom(%) ; end proc: # _R. J. Mathar_, Jul 01 2011
%t Denominator[1-Accumulate[BernoulliB[Range[0,40]]]] (* _Harvey P. Dale_, Feb 19 2015 *)
%o (PARI) a(n) = denominator(1 - sum(i=1, n, bernfrac(i))); \\ _Michel Marcus_, Feb 15 2021
%Y Cf. A002110
%K nonn,frac
%O 0,2
%A _N. J. A. Sloane_, Dec 05 2004