OFFSET
1,2
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
EXAMPLE
a(12) = a(11) + product of digits of 11 = 46 + 1 = 47.
MATHEMATICA
a[n_] := a[n] = (a[n - 1] + Times @@ IntegerDigits[n - 1]); a[1] = 1; Table[ a[n], {n, 1, 60}]
nxt[{n_, a_}]:={n+1, a +Times@@IntegerDigits[n]}; NestList[nxt, {1, 1}, 70][[All, 2]] (* Harvey P. Dale, Jan 23 2021 *)
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Joseph L. Pe, May 09 2002
EXTENSIONS
Edited by Robert G. Wilson v, May 14 2002
Corrected and extended by Harvey P. Dale, Jan 23 2021
STATUS
approved