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A070280
a(1) = 1; a(n) = a(n-1) + product of the digits of n-1.
1
1, 2, 4, 7, 11, 16, 22, 29, 37, 46, 46, 47, 49, 52, 56, 61, 67, 74, 82, 91, 91, 93, 97, 103, 111, 121, 133, 147, 163, 181, 181, 184, 190, 199, 211, 226, 244, 265, 289, 316, 316, 320, 328, 340, 356, 376, 400, 428, 460, 496, 496, 501, 511, 526, 546, 571, 601, 636, 676, 721, 721, 727, 739, 757, 781, 811, 847, 889, 937, 991, 991
OFFSET
1,2
LINKS
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
Sequence in context: A348575 A348400 A025726 * A025707 A337919 A025733
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