A029490 Numbers k that divide the (left) concatenation of all numbers <= k written in base 21 (most significant digit on left).

1, 5, 25, 43, 55, 128, 275, 1280, 2816, 5888, 6400, 12800, 28160, 33413, 37376, 129919, 140800, 286025, 352000, 990845, 1050880, 1773725, 2848000, 3581033, 4343680, 4428160, 5624960, 6732160, 7553920, 8497280, 9249995, 9872000, 10938752, 11426176, 14558575, 14569600, 15368320, 18998705, 19312000, 21362275, 24208000, 24934855, 27632000, 32432000, 37022605, 43193216, 51382265, 53717375, 81016375

Offset

1,2

Comments

a(62) > 3*10^10. - Jason Yuen, Jun 29 2024

Links

Jason Yuen, Table of n, a(n) for n = 1..61

Index entries for related sequences

Mathematica

b = 21; c = {}; Select[Range[10^4], Divisible[FromDigits[c = Join[IntegerDigits[#, b], c], b], #] &] (* Robert Price, Mar 12 2020 *)

Crossrefs

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

Sequence in context: A293571 A294256 A056872 * A223654 A362092 A098947

Adjacent sequences: A029487 A029488 A029489 * A029491 A029492 A029493

Keyword

nonn,base

Author

Olivier Gérard

Extensions

More terms from Andrew Gacek (andrew(AT)dgi.net), Feb 21 2000

More terms from Larry Reeves (larryr(AT)acm.org), May 24 2001

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

a(20)-a(49) from Max Alekseyev, May 15 2011

Status

approved