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 A192986 Numerator of Sum_{i=0..n-1} B(i)/B(n), where B(i) = A000110(i) are the Bell numbers. 2
 0, 1, 1, 4, 3, 6, 76, 279, 289, 5296, 26443, 71209, 820988, 5034585, 16339511, 223578344, 1606536889, 1007223253, 94951548840, 777028354999, 1652442640014, 58333928795428, 533203744952179, 2519959741699751, 49191925338483848, 495150794633289137, 2566870563431644245 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,4 LINKS G. C. Greubel, Table of n, a(n) for n = 0..500 R. Kaye, A Gray code for set partitions, Info. Proc. Letts., 5 (1976), 171-173. EXAMPLE 0, 1, 1, 4/5, 3/5, 6/13, 76/203, 279/877, 289/1035, 5296/21147, 26443/115975, ... MATHEMATICA Table[Numerator[Sum[BellB[j], {j, 0, n-1}]/BellB[n]], {n, 0, 30}] (* G. C. Greubel, Jul 25 2019 *) PROG (PARI) bell(n)=sum(k=0, n, stirling(n, k, 2)); vector(30, n, n--; numerator( sum(j=0, n-1, bell(j))/bell(n)) ) \\ G. C. Greubel, Jul 25 2019 (MAGMA) [0] cat [Numerator((&+[Bell(j): j in [0..n-1]])/Bell(n)): n in [1..30]]; // G. C. Greubel, Jul 25 2019 (Sage) [numerator(sum(bell_number(j) for j in (0..n-1))/bell_number(n)) for n in (0..30)] # G. C. Greubel, Jul 25 2019 (GAP) List([0..30], n-> NumeratorRat(Sum([0..n-1], j-> Bell(j))/Bell(n)) ); # G. C. Greubel, Jul 25 2019 CROSSREFS Cf. A000110, A192987. Sequence in context: A276229 A077955 A077978 * A336741 A072816 A340012 Adjacent sequences:  A192983 A192984 A192985 * A192987 A192988 A192989 KEYWORD nonn,frac AUTHOR N. J. A. Sloane, Jul 13 2011 STATUS approved

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Last modified December 6 13:24 EST 2021. Contains 349563 sequences. (Running on oeis4.)