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.

A358705 Zeroless pandigital numbers whose square has each digit 1 to 9 twice.

Original entry on oeis.org

345918672, 351987624, 359841267, 394675182, 429715863, 439516278, 487256193, 527394816, 527498163, 528714396, 572493816, 592681437, 729564183, 746318529, 749258163, 754932681, 759142683, 759823641, 762491835, 783942561, 784196235, 845691372, 891357624, 914863275, 915786423, 923165487, 928163754, 976825431
Offset: 1

Views

Author

Zhining Yang, Nov 27 2022

Keywords

Examples

			345918672 is a term since its square 119659727638243584 contains all digits 1..9 twice each.
		

Crossrefs

Programs

  • Maple
    R:= NULL:
    for t in combinat:-permute([$1..9]) do
      x:= add(t[i]*10^(i-1),i=1..9);
      if sort(convert(x^2,base,10)) = [seq(i$2,i=1..9)] then
        R:= R, x
      fi
    od:
    sort([R]); # Robert Israel, Nov 27 2022
  • Python
    from itertools import permutations as per
    a=[]
    for n in [int(''.join(d)) for d in per('123456789', 9)]:
        if all(str(n**2).count(d) ==2 for d in '123456789'):
            a.append(n)
    print(a)