The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 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 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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

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