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 A260526 Concatenate the positions of digits 0, 1,..., 9 in the decimal representation of n, using 1 for the rightmost digit etc., skip it if a digit does not occur. 3
 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 12, 12, 21, 21, 21, 21, 21, 21, 21, 21, 12, 12, 12, 21, 21, 21, 21, 21, 21, 21, 12, 12, 12, 12, 21, 21, 21, 21, 21, 21, 12, 12, 12, 12, 12, 21, 21, 21, 21, 21, 12, 12, 12, 12, 12, 12, 21, 21, 21, 21, 12, 12, 12, 12, 12, 12, 12, 21, 21 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,11 COMMENTS Sequence A260274 lists fixed points of this function. Sequence A260519 is the same except for concatenating a 0 for digits which do not occur. LINKS EXAMPLE Consider n=1103, the digit '0' is at 2nd position (looking from the right), digit '1' in 3rd and 4th place, digit '3' at 1st position, digits 2 and 4-9 do not occur. Thus a(1103) = 2341. PROG (PARI) a(n)={my(p=vector(10)); for(i=1, #n=if(n, Vecrev(digits(n)), [0]), p[n[i]+1]=if(p[n[i]+1], concat(p[n[i]+1], i), i)); if(1<#p=concat(select(t->#t, p)), p[1]=Str(p[1]); eval(concat(p)), p)} CROSSREFS Cf. A260527 - A260529 and A260519 - A260522 for variants; A045918 for the classical "look and say" sequence. Sequence in context: A061074 A064161 A260528 * A040133 A092538 A309772 Adjacent sequences:  A260523 A260524 A260525 * A260527 A260528 A260529 KEYWORD nonn,base AUTHOR M. F. Hasler, Jul 28 2015 STATUS approved

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Last modified May 24 05:29 EDT 2022. Contains 354005 sequences. (Running on oeis4.)