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.

A225218 Square numbers containing all the digits 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9.

Original entry on oeis.org

1026753849, 1042385796, 1098524736, 1237069584, 1248703569, 1278563049, 1285437609, 1382054976, 1436789025, 1503267984, 1532487609, 1547320896, 1643897025, 1827049536, 1927385604, 1937408256, 2076351489, 2081549376, 2170348569, 2386517904, 2431870596
Offset: 1

Views

Author

Reiner Moewald, May 02 2013

Keywords

Comments

The first term having a repeated digit is 10057482369. - Colin Barker, Jan 15 2014

Examples

			1026753849 is in the sequence because 1026753849 = 32043^2 and 1026753849 contains all ten digits 0, ..., 9.
		

Crossrefs

Supersequence of A036745.

Programs

  • Mathematica
    Select[#^2 &[Range[1000000]], Length[Union[IntegerDigits[#]]] == 10 &] (* Geoffrey Critzer, Jan 04 2015 *)
  • PARI
    s=[]; for(n=1, 100000, if(#vecsort(eval(Vec(Str(n^2))), , 8)==10, s=concat(s, n^2))); s \\ Colin Barker, Jan 15 2014
    
  • Python
    from itertools import count, islice
    def c(n): return len(set(str(n))) == 10
    def agen(): yield from (k*k for k in count(31622) if c(k*k))
    print(list(islice(agen(), 21))) # Michael S. Branicky, Dec 27 2022

Formula

a(n) = A054038(n)^2. - Colin Barker, Jan 15 2014