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A283195 Clone sequence C(2,3): a(1) = 1; for n > 1, a(n) is obtained by repeating each digit of a(n-1), summing the digits in groups of 3, and concatenating the digits of the sums. 0
1, 2, 4, 8, 16, 86, 226, 614, 139, 521, 124, 410, 91, 191, 1111, 332, 97, 257, 919, 1919, 111118, 33317, 9997, 272714, 1111159, 3331118, 993316, 2715713, 1191796, 31992512, 719201242, 15194288, 77228248, 21111212168, 533544208, 1391412416 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

The sequence of digital roots of a(n) has period 6: 1, 2, 4, 8, 7, 5.

LINKS

Table of n, a(n) for n=1..36.

FORMULA

a(n) = concat(s1,s2,s3,...) where sj is the sum of the j-th set of three digits in the "cloned" digit string obtained by repeating each digit of a(n-1).

EXAMPLE

a(9) is obtained from a(8) = 614 by cloning every digit of 614 to get 6,6,1,1,4,4, summing the digits three at a time to get (6+6+1, 1+4+4) = (13, 9), and concatenating the sums to get a(9) = 139.

a(1) = 1, so a(2) = 1 + 1 + 0 = 2;

a(5) = 16, so a(6) = concat(1 + 1 + 6, 6 + 0 + 0) = 86;

a(6) = 86, so a(7) = concat(8 + 8 + 6, 6 + 0 + 0) = 226;

a(7) = 226, so a(8) = concat(2 + 2 + 2, 2 + 6 + 6) = 614;

a(8) = 614, so a(9) = concat(6 + 6 + 1, 1 + 4 + 4) = 139.

MATHEMATICA

NestList[FromDigits@ Flatten@ Map[IntegerDigits@ Total@ # &, Partition[PadRight[#, 3 Ceiling[Length@ #/3]], 3, 3]] &@ Riffle[#, #] &@ IntegerDigits@ # &, 1, 35] (* Michael De Vlieger, Mar 03 2017 *)

CROSSREFS

Sequence in context: A097049 A119490 A013174 * A233294 A287706 A287705

Adjacent sequences:  A283192 A283193 A283194 * A283196 A283197 A283198

KEYWORD

nonn,base,easy

AUTHOR

Medjber Mohamed Mounir, Mar 02 2017

STATUS

approved

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Last modified December 4 15:36 EST 2021. Contains 349526 sequences. (Running on oeis4.)