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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 (list; graph; refs; listen; history; text; internal format)
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

Sequence in context: A025702 A025717 A025726 * A025707 A337919 A025733

Adjacent sequences:  A070277 A070278 A070279 * A070281 A070282 A070283

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

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Last modified October 18 18:43 EDT 2021. Contains 348068 sequences. (Running on oeis4.)