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 A044821 Positive integers having distinct base-10 run lengths. 18
 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 22, 33, 44, 55, 66, 77, 88, 99, 100, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 122, 133, 144, 155, 166, 177, 188, 199, 200, 211, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 233, 244, 255 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS David A. Corneth, Table of n, a(n) for n = 1..10000 EXAMPLE 117 is in the sequence because it has a run length of 2 and a run length of 1. 101 is not in the sequence because it has three run lengths of 1. - R. J. Mathar, Jan 18 2018 MAPLE rlset := proc(L::list) local lset, rl, i ; lset := [] ; rl := 1 ; for i from 2 to nops(L) do if op(i, L) = op(i-1, L) then rl := rl+1 ; else lset := [op(lset), rl] ; rl := 1; end if; end do: lset := [op(lset), rl] ; end proc: isA044821 := proc(n) local dgs, rl; dgs := convert(n, base, 10) ; rl := rlset(dgs) ; if nops(rl) = nops( convert(rl, set)) then true; else false; end if; end proc: for n from 1 to 400 do if isA044821(n) then printf("%d, ", n) ; end if; end do: # R. J. Mathar, Jan 18 2018 PROG (Python) from itertools import groupby def ok(n): runlengths = [len(list(g)) for k, g in groupby(str(n))] return len(runlengths) == len(set(runlengths)) print([i for i in range(1, 256) if ok(i)]) # Michael S. Branicky, Jan 04 2021 (PARI) is(n) = { my(runs = List(), lr = 0, d = digits(n)); for(i = 1, #d - 1, if(d[i] != d[i + 1], listput(runs, i - lr); lr = i; ) ); listput(runs, #d - lr); #Set(runs) == #runs } \\ David A. Corneth, Jan 04 2021 CROSSREFS Cf. A044813, A044814, A044815, A044816, A044817, A044818, A044819, A044820, A044821, A044822, A044823, A044824, A044825, A044826, A044827 (base 2 to base 16). Sequence in context: A353181 A306273 A141033 * A297148 A048307 A043713 Adjacent sequences: A044818 A044819 A044820 * A044822 A044823 A044824 KEYWORD nonn,base AUTHOR Clark Kimberling STATUS approved

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Last modified June 19 06:35 EDT 2024. Contains 373492 sequences. (Running on oeis4.)