A113904 Starting with 1, each number is the previous number plus the product of the index number and the sum of the digits of the previous number.

1, 2, 6, 24, 48, 108, 162, 225, 297, 459, 639, 837, 1053, 1170, 1296, 1566, 1854, 2160, 2322, 2493, 2853, 3231, 3429, 3843, 4275, 4725, 5193, 5679, 6435, 6957, 7767, 8604, 9180, 9774, 10692, 11322, 11646, 12312, 12654, 13356, 14076, 14814, 15570, 16344

Offset

1,2

Links

Table of n, a(n) for n=1..44.

Formula

a(n) = a(n-1)+(n-1)*s(n-1), where s(n) stands for the sum of the digits of n.

Example

a(6) = a(5)+ 5*s(a(5)) = 48+5*s(48) = 48+5*12 = 108

Mathematica

nxt[{n_, a_}]:={n+1, a+(n+1)Total[IntegerDigits[a]]}; Transpose[NestList[ nxt, {0, 1}, 50]][[2]] (* Harvey P. Dale, Jun 25 2013 *)

Crossrefs

Sequence in context: A000496 A004306 A092485 * A099144 A354216 A189851

Adjacent sequences: A113901 A113902 A113903 * A113905 A113906 A113907

Keyword

base,easy,nonn

Author

Luc Stevens (lms022(AT)yahoo.com), Apr 20 2006

Extensions

Corrected by Harvey P. Dale, Jun 25 2013

Status

approved