A271220 - OEIS

A271220

Concatenate sum of digits of previous term and product of digits of previous term, starting with 6.

6, 66, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236, 1236

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OFFSET

1,1

COMMENTS

Each term is created by calculating the sum of the digits of the previous number, and the product of its digits. The results are concatenated to give the new number. Starting with 6, the second number is 66. The third number is generated as follows: 6+6=12, 6*6=36, which gives 1236. After that, the numbers remain unchanged, because 1+2+3+6=12 and 1x2x3x6=36, so combined 1236 again.

LINKS

Table of n, a(n) for n=1..51.

MATHEMATICA

NestList[FromDigits[Flatten@ {IntegerDigits@ Total@ #, IntegerDigits@ If[Length@ # == 1, #, Times @@ #]}] &@ IntegerDigits@ # &, 6, 50] (* Michael De Vlieger, Apr 02 2016 *)

CROSSREFS

Sequence in context: A262601 A329930 A367308 * A259123 A292026 A126459

Adjacent sequences: A271217 A271218 A271219 * A271221 A271222 A271223

KEYWORD

nonn,base

AUTHOR

Sander Claassen, Apr 02 2016

STATUS

approved