A066976 a(0) = 1; for n>0: a(n) = sum{a(i)*n^i : 0<=i<n}.

1, 1, 3, 31, 2037, 1277081, 9933228619, 1168655882598723, 2450851625481815985865, 105501131724162360454576400809, 105501131969247534689326758739077501311, 2736427656021274732181782085698646439681516475371

Offset

0,3

Links

Reinhard Zumkeller, Table of n, a(n) for n = 0..32

Example

a(3) = a(0)*3^0 + a(1)*3^1 + a(2)*3^2 = 1*1 + 1*3 + 3*9 = 31.

Maple

a:= proc(n) option remember;
      `if`(n=0, 1, add(a(i)*n^i, i=0..n-1))
    end:
seq(a(n), n=0..15); # Alois P. Heinz, Aug 21 2011

Mathematica

a[0] = 1; a[n_] := Sum[a[i]*n^i, {i, 0, n-1}]; Table[a[n], {n, 0, 11}] (* Jean-François Alcover, Mar 24 2014 *)

Prog

(Haskell)
a066976 0 = 1
a066976 n = sum $ zipWith (*) a066976_list $ map (n ^) [0..n-1]
a066976_list = map a066976 [0..]
-- Reinhard Zumkeller, Oct 25 2011

Crossrefs

Sequence in context: A141153 A144906 A081789 * A172645 A201604 A048562

Adjacent sequences: A066973 A066974 A066975 * A066977 A066978 A066979

Keyword

nonn,nice

Author

Reinhard Zumkeller, Jan 26 2002

Status

approved