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 A158265 G.f.: A(x) = exp( Sum_{n>=1} 2*sigma(n,n+1)*x^n/n ). 0
 1, 2, 11, 74, 697, 8002, 115158, 1949640, 38662510, 872245634, 22150393253, 623661939852, 19296665400632, 650198159192554, 23700604926216759, 928939297013294294, 38956230043045053042, 1740248411222193973416 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Definition: sigma(n,n+1) = Sum_{d|n} d^(n+1): [1,9,82,1057,15626,...]. LINKS EXAMPLE G.f.: A(x) = 1 + 2*x + 11*x^2 + 74*x^3 + 697*x^4 + 8002*x^5 +... log(A(x)) = 2*x + 18*x^2/2 + 164*x^3/3 + 2114*x^4/4 + 31252*x^5/5 +... PROG (PARI) a(n)=polcoeff(exp(sum(m=1, n, 2*sigma(m, m+1)*x^m/m)+x*O(x^n)), n) CROSSREFS Cf. A158095, A023881. Sequence in context: A058789 A212028 A324445 * A321387 A309146 A198088 Adjacent sequences:  A158262 A158263 A158264 * A158266 A158267 A158268 KEYWORD nonn AUTHOR Paul D. Hanna, Mar 29 2009 STATUS approved

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Last modified December 8 02:41 EST 2021. Contains 349590 sequences. (Running on oeis4.)