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 A226854 a(n) = (-5*B(n+2) + (2*n+9)*B(n+1) + (2*n+1)*B(n))/4, where the B(i) are Bell numbers (A000110). 1
 0, 0, 0, 0, 1, 11, 89, 660, 4795, 35067, 261505, 2001608, 15777434, 128270836, 1076208942, 9318227402, 83230080505, 766465520673, 7272362469647, 71040825568988, 713933196773609 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,6 LINKS Vincenzo Librandi, Table of n, a(n) for n = 0..200 B. Chern, P. Diaconis, D. M. Kane, R. C. Rhoades, Closed expressions for averages of set partition statistics, 2013. MATHEMATICA Table[(-5 BellB[n+2] + (2 n + 9) BellB[n + 1] + (2 n + 1) BellB[n])/4, {n, 0, 30}] (* Vincenzo Librandi Jul 16 2013 *) PROG (PARI) B(n) = if (n<=1, return (1), return (sum(i=0, n-1, binomial(n-1, i)*B(n-1-i)))) a(n) = (-5*B(n+2) + (2*n+9)*B(n+1) + (2*n+1)*B(n))/4 (MAGMA) [(-5*Bell(n+2)+(2*n+9)*Bell(n+1)+(2*n+1)*Bell(n))/4: n in [0..30]]; // Vincenzo Librandi, Jul 16 2013 CROSSREFS Sequence in context: A121155 A201117 A081657 * A037580 A155607 A110252 Adjacent sequences:  A226851 A226852 A226853 * A226855 A226856 A226857 KEYWORD nonn AUTHOR Michel Marcus, Jun 19 2013 STATUS approved

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Last modified August 5 22:09 EDT 2020. Contains 336214 sequences. (Running on oeis4.)