A029471 Numbers k that divide the (left) concatenation of all numbers <= k written in base 2 (most significant digit on left).
1, 85, 145, 245, 1189, 356717, 19590671, 35741759, 791822369, 25313027035
Offset: 1
Crossrefs
Programs
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Mathematica
b = 2; c = {}; Select[Range[10^4], Divisible[FromDigits[c = Join[IntegerDigits[#, b], c], b], #] &] (* Robert Price, Mar 12 2020 *) -
Python
from itertools import count def a029471(): total = 0 power_of_two = 1 index_of_two = 0 length_of_string = 0 for n in count(1): total += (n< -
Python
def concat_mod(base, k, mod): ... # See A029479 for k in range(1, 3*10**10): if concat_mod(2, k, k) == 0: print(k) # Jason Yuen, Mar 24 2024
Extensions
One more term from Larry Reeves (larryr(AT)acm.org), Dec 03 2001
Edited and updated by Larry Reeves (larryr(AT)acm.org), Apr 12 2002
a(7)-a(8) from Max Alekseyev, May 12 2011
a(9)-a(10) from Jason Yuen, Mar 24 2024
Comments