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 A000424 Differences of reciprocals of unity. (Formerly M4448 N1883) 4
 7, 85, 1660, 48076, 1942416, 104587344, 7245893376, 628308907776, 66687811660800, 8506654697548800, 1284292319599411200, 226530955276874956800, 46165213716463676620800, 10765453901922078105600000, 2848453606917036402278400000, 848800150518516674081587200000 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 REFERENCES F. N. David, M. G. Kendall and D. E. Barton, Symmetric Function and Allied Tables, Cambridge, 1966, p. 228. M. Merca, Some experiments with complete and elementary symmetric functions. - Periodica Mathematica Hungarica, 69 (2014), 182-189. N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence). N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). LINKS FORMULA From Vaclav Kotesovec, Oct 23 2017: (Start) a(n) = (3*n^2 + 3*n + 1)*a(n-1) - 3*n^4*a(n-2) + (n-1)^3*n^3*a(n-3). a(n) ~ Pi * log(n)^2 * n^(2*n + 3) * (1 + 2*gamma/log(n) + (gamma^2 + Pi^2/6) / log(n)^2) / exp(2*n), where gamma is the Euler-Mascheroni constant (A001620). (End) MATHEMATICA T[n_, k_] := If[k <= n, (n-k+2)!^k*Sum[(-1)^(j+1)*Binomial[n-k+2, j]/j^k, {j, 1, n-k+2}], 0]; a[n_] := T[n+1, 2]; Table[a[n], {n, 1, 10}] (* Jean-François Alcover, Feb 08 2016, after Alois P. Heinz in A008969 *) CROSSREFS Essentially the same as A060237. Column 2 in triangle A008969. Sequence in context: A293055 A121020 A060237 * A207214 A000686 A102923 Adjacent sequences:  A000421 A000422 A000423 * A000425 A000426 A000427 KEYWORD nonn AUTHOR EXTENSIONS More terms from Vaclav Kotesovec, Oct 23 2017 STATUS approved

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