A045879 Numbers whose square contains the same digits as some other square.

12, 13, 14, 16, 21, 25, 31, 32, 33, 36, 37, 42, 44, 49, 54, 64, 69, 96, 98, 99, 101, 102, 103, 106, 108, 110, 112, 113, 120, 122, 128, 129, 130, 133, 135, 137, 140, 144, 146, 148, 152, 153, 154, 155, 157, 158, 159, 160, 166, 172, 174, 178, 179, 181, 186, 190

Offset

1,1

Links

David A. Corneth, Table of n, a(n) for n = 1..10000

Example

12^2 = 144 has same digits as 21^2 = 441, so 12 and 21 are in the sequence.

Prog

(PARI) uptoqdigits(n) = { res = List(); for(i = 3, n, withqdigits(i); ); Set(res); }
withqdigits(n) = { my(l = List(), streak); for(i = sqrtint(10^(n-1)), sqrtint(10^n-1), listput(l, [vecsort(digits(i^2)), i])); listsort(l); print(#l); for(i = 1, #l-1, if(l[i][1] == l[i+1][1], listput(res, l[i][2]); streak = 1; , if(streak == 1, listput(res, l[i][2])); streak = 0)); if(streak == 1, listput(res, l[#l][2])); } \\ David A. Corneth, Aug 13 2021

Crossrefs

Cf. A000290.

Sequence in context: A272270 A133894 A209725 * A257073 A239722 A112655

Adjacent sequences: A045876 A045877 A045878 * A045880 A045881 A045882

Keyword

nonn,base

Author

Erich Friedman

Status

approved