A061972 - OEIS

A061972

Numbers n such that n divides the (left) concatenation of all numbers <= n written in base 19 (most significant digit on right).

%I #13 Mar 09 2020 22:00:12

%S 1,3,9,27,33,36,81,183,223,261,263,351,585,1035,1092,1173,1732,2235,

%T 2628,3492,8577,11592,13617,15663,20664,20709,23333,25848,52689,67608,

%U 334536,837112,2765341,5319444

%N Numbers n such that n divides the (left) concatenation of all numbers <= n written in base 19 (most significant digit on right).

%C This sequence differs from A029536 in that all least significant zeros are kept during concatenation.

%C No more terms < 7*10^6.

%H <a href="/index/N#concat">Index entries for related sequences</a>

%e See A061955 for example.

%t b = 19; c = {}; Select[Range[10^4], Divisible[FromDigits[c = Join[Reverse[IntegerDigits[#, b]], c], b], #] &] (* _Robert Price_, Mar 09 2020 *)

%Y Cf. A029447-A029470, A029471-A029494, A029495-A029518, A029519-A029542, A061931-A061954, A061955-A061978.

%K nonn,base,more

%O 1,2

%A Larry Reeves (larryr(AT)acm.org), May 24 2001

%E Edited and updated by Larry Reeves (larryr(AT)acm.org), Apr 12 2002

%E a(32)-a(34) from _Lars Blomberg_, Jul 31 2011