A074401 2^n contains all divisors of n as substrings.

37, 51, 67, 89, 93, 179, 191, 373, 391, 445, 478, 479, 519, 521, 551, 581, 583, 601, 613, 619, 653, 655, 661, 673, 697, 701, 703, 713, 719, 727, 753, 759, 769, 773, 778, 851, 853, 881, 886, 889, 907, 913, 919, 923, 949, 973, 974

Offset

1,1

Links

Table of n, a(n) for n=1..47.

Example

2^51 = 2251799813685248, which contains the divisors of 51, i.e. 1, 3, 17, 51, as substrings, so 51 belongs to the sequence.

Mathematica

a = {}; Do[d = Divisors[i]; l = Length[d]; r = True; s = ToString[2^i]; For[j = 1, j <= l, j++, If[StringPosition[s, ToString[d[[j]]]] == {}, r = False; Break] ]; If[r == True, a = Append[a, i]], {i, 1, 10^3}]; a

Crossrefs

Sequence in context: A297911 A253019 A298504 * A323476 A345169 A350250

Adjacent sequences: A074398 A074399 A074400 * A074402 A074403 A074404

Keyword

base,nonn

Author

Joseph L. Pe, Sep 25 2002

Status

approved