cp's OEIS Frontend

A178246 Numbers m such that all digits of m, including repetitions, occur among the digits of 2^m.

%I A178246 #33 Jan 30 2022 14:02:14
%S A178246 6,10,14,17,21,25,27,28,29,30,31,35,36,37,39,44,45,46,47,48,49,50,51,
%T A178246 52,54,56,57,58,60,61,62,63,64,66,67,68,69,70,72,73,74,75,76,77,79,80,
%U A178246 81,82,83,84,85,86,87,88,89,90,92,93,94,95,96,97,98,100,101,102,103,104,105,106,107,108,109,110,111,113,114,115,116,117
%N A178246 Numbers m such that all digits of m, including repetitions, occur among the digits of 2^m.
%C A178246 The sequence shows subsets of consecutive numbers.
%C A178246 153 is assumed to be the largest integer missing in this sequence. - _Alois P. Heinz_, Jan 28 2022
%H A178246 Michel Marcus, <a href="/A178246/b178246.txt">Table of n, a(n) for n = 1..962</a>
%e A178246 17 is a term because the digits 1 and 7 are included in the number 2^17 = 131072;
%e A178246 3 is not a term because the digit 3 is not in the number 2^3 = 8.
%e A178246 33 is not a term because 2^33 = 8589934592 does not have 2 digits 3.
%e A178246 153 is not in the sequence because the digit 3 is not in the number 2^153 = 11417981541647679048466287755595961091061972992.
%t A178246 Reap[Do[a = DigitCount[2^n]; b = DigitCount[n]; If[Min[a-b] >= 0, Sow[n]], {n, 10^3}]][[2, 1]]
%o A178246 (PARI) isok(m) = {my(d=digits(m), dd=digits(2^m)); for (i=0, 9, if (#select(x->(x==i), d) > #select(x->(x==i), dd), return (0));); return(1);} \\ _Michel Marcus_, Jan 28 2022
%Y A178246 Cf. A000079, A064827, A032740.
%K A178246 nonn,base
%O A178246 1,1
%A A178246 _Michel Lagneau_, Dec 20 2010
%E A178246 Name clarified by _Michel Marcus_, Jan 30 2022