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%I #36 Jul 26 2021 01:45:43
%S 1,4,5,7,19,443,19952,81544,919648,1186844
%N Numbers k such that k divides the (left) concatenation of all numbers <= k written in base 3 (most significant digit on right).
%C This sequence differs from A061956 in that all least significant zeros are removed before concatenation.
%C No more terms < 10^7. [_Lars Blomberg_, Sep 02 2011]
%H <a href="/index/N#concat">Index entries for related sequences</a>
%e See A029519 for example.
%t b = 3; c = {}; Select[Range[10^4], Divisible[FromDigits[c = Join[IntegerDigits[IntegerReverse[#, b], b], c], b], #] &] (* _Robert Price_, Mar 13 2020 *)
%o (J) ab=. #.^:_1
%o mkcat=. [ ab&.> [ #.&.> [ |.@:ab&.> [: |. [: >: [: i. ]
%o seq=. ] +. [ #. [: ; mkcat
%o 3 (] #~ ] = seq"0) >: i.500x NB. _Stephen Makdisi_, May 03 2018
%Y Cf. A029447-A029470, A029471-A029494, A029495-A029518, A029519-A029542, A061931-A061954, A061955-A061978.
%K nonn,base,more
%O 1,2
%A _Olivier Gérard_
%E Edited and updated by Larry Reeves (larryr(AT)acm.org), Apr 12 2002
%E Additional comments and more terms from Larry Reeves (larryr(AT)acm.org), Jun 04 2001
%E a(9)-a(10) from _Lars Blomberg_, Sep 02 2011
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