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This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A323339 Numerator of the sum of inverse products of parts in all compositions of n.

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%I A323339 #23 Feb 12 2024 07:57:53
%S A323339 1,1,3,7,11,347,3289,1011,38371,136553,4320019,12528587,40771123,
%T A323339 29346499543,129990006917,1927874590951,903657004321,437445829053473,
%U A323339 12456509813711881,187206004658210129,1974369484466728177,1967745662306280217,21401375717067880189
%N A323339 Numerator of the sum of inverse products of parts in all compositions of n.
%C A323339 Numerators of the INVERT transform of reciprocal integers.
%H A323339 Alois P. Heinz, <a href="/A323339/b323339.txt">Table of n, a(n) for n = 0..466</a>
%F A323339 G.f. for fractions: 1 / (1 + log(1 - x)). - _Ilya Gutkovskiy_, Nov 12 2019
%F A323339 a(n) = numerator( A007840(n)/n! ). - _Alois P. Heinz_, Jan 04 2024
%F A323339 A323339(n)/A323340(n) ~ exp(n) / (exp(1) - 1)^(n+1). - _Vaclav Kotesovec_, Feb 12 2024
%e A323339 1/1, 1/1, 3/2, 7/3, 11/3, 347/60, 3289/360, 1011/70, 38371/1680, 136553/3780, 4320019/75600, 12528587/138600, 40771123/285120, ... = A323339/A323340
%p A323339 b:= proc(n) option remember;
%p A323339      `if`(n=0, 1, add(b(n-j)/j, j=1..n))
%p A323339     end:
%p A323339 a:= n-> numer(b(n)):
%p A323339 seq(a(n), n=0..25);
%t A323339 nmax = 20; Numerator[CoefficientList[Series[1/(1 + Log[1-x]), {x, 0, nmax}], x]] (* _Vaclav Kotesovec_, Feb 12 2024 *)
%Y A323339 Denominators: A323340.
%Y A323339 Cf. A000142, A007840, A011782, A088305, A177208, A177209, A322364, A322365, A322380, A322381, A323290, A323291.
%K A323339 nonn,frac
%O A323339 0,3
%A A323339 _Alois P. Heinz_, Jan 11 2019