cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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

Original entry on oeis.org

6, 10, 14, 17, 21, 25, 27, 28, 29, 30, 31, 35, 36, 37, 39, 44, 45, 46, 47, 48, 49, 50, 51, 52, 54, 56, 57, 58, 60, 61, 62, 63, 64, 66, 67, 68, 69, 70, 72, 73, 74, 75, 76, 77, 79, 80, 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
Offset: 1

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Author

Michel Lagneau, Dec 20 2010

Keywords

Comments

The sequence shows subsets of consecutive numbers.
153 is assumed to be the largest integer missing in this sequence. - Alois P. Heinz, Jan 28 2022

Examples

			17 is a term because the digits 1 and 7 are included in the number 2^17 = 131072;
3 is not a term because the digit 3 is not in the number 2^3 = 8.
33 is not a term because 2^33 = 8589934592 does not have 2 digits 3.
153 is not in the sequence because the digit 3 is not in the number 2^153 = 11417981541647679048466287755595961091061972992.
		

Crossrefs

Programs

  • Mathematica
    Reap[Do[a = DigitCount[2^n]; b = DigitCount[n]; If[Min[a-b] >= 0, Sow[n]], {n, 10^3}]][[2, 1]]
  • 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

Extensions

Name clarified by Michel Marcus, Jan 30 2022