The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A191491 Diagonal sums of triangle A191490. 2
 1, 1, 2, 3, 7, 14, 35, 86, 235, 660, 1968, 6078, 19570, 65129, 224057, 793794, 2892656, 10819274, 41480851, 162783153, 653115031, 2676107761, 11187573667, 47675621875, 206936072980, 914179405191, 4107584622566, 18759751255220, 87036191538839, 409986093418733 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS Vincenzo Librandi, Table of n, a(n) for n = 0..104 MATHEMATICA f[n_, k_] := f[n, k] = f[n - 1, k] + (n - 1)f[n - 1, k - 1] + If[n == k, 1, 0] f[_, 0] = 1; f[0, _] = 0; Table[Sum[f[n - k, k], {k, 0, n}], {n, 0, 100}] PROG (Maxima) P[0]:1\$ P[n]:=(1+(n-1)*q)*P[n-1]+q^n\$ makelist(sum(coeff(expand(P[n-k]), q^k), k, 0, n), n, 0, 24); CROSSREFS Cf. A191490. Sequence in context: A180564 A113822 A036250 * A210345 A006660 A306844 Adjacent sequences:  A191488 A191489 A191490 * A191492 A191493 A191494 KEYWORD nonn AUTHOR Emanuele Munarini, Jun 03 2011 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified May 27 20:17 EDT 2020. Contains 334667 sequences. (Running on oeis4.)