A076929 a(1) = 1, a(n+1)= a(n)*(n+1) divided by the smallest prime divisor of n+1.

1, 1, 1, 2, 2, 6, 6, 24, 72, 360, 360, 2160, 2160, 15120, 75600, 604800, 604800, 5443200, 5443200, 54432000, 381024000, 4191264000, 4191264000, 50295168000, 251475840000, 3269185920000, 29422673280000, 411917425920000

Offset: 1

Author

Amarnath Murthy, Oct 18 2002

Keywords

• nonn

Crossrefs

Cf. A076928.

Programs

Maple

a[1] := 1: for n from 2 to 100 do a[n] := n*a[n-1]/ifactors(n)[2][1][1]: od:seq(a[j],j=1..100);

Mathematica

nxt[{n_,a_}]:={n+1,(a(n+1))/FactorInteger[n+1][[1,1]]}; Transpose[ NestList[ nxt,{1,1},30]][[2]] (* Harvey P. Dale, Jan 09 2016 *)

Extensions

More terms from Sascha Kurz, Jan 21 2003