A074703 a(n) = n^2*a(n-1)+1, a(1)=0.
0, 1, 10, 161, 4026, 144937, 7101914, 454522497, 36816322258, 3681632225801, 445477499321922, 64148759902356769, 10841140423498293962, 2124863523005665616553, 478094292676274763724426
Offset: 1
Links
- Harvey P. Dale, Table of n, a(n) for n = 1..253
Programs
-
Mathematica
nxt[{n_,a_}]:={n+1,(n+1)^2 a+1}; Transpose[NestList[nxt,{1,0},20]][[2]] (* Harvey P. Dale, Dec 11 2013 *) -
PARI
a(n)=round((besseli(0,2)-2)*n!^2) \\ Charles R Greathouse IV, Feb 19 2014
Formula
a(n) = round(n!^2*(BesselI(0, 2)-2)).