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.

A202239 n such that the sum of the factorials of the digits of n equals the sum of d|n, 1

Original entry on oeis.org

620, 13407, 66061, 266533, 282401, 416641, 3507607, 7036153, 7622243, 10327663, 17735167, 34802143, 57653483, 86357113, 86546363, 91203611, 112777747, 121825337, 124283381, 127316869, 176080309, 216687451, 218172511, 231811037, 243238447, 263364883, 272368301
Offset: 1

Views

Author

Michel Lagneau, Dec 16 2011

Keywords

Examples

			620 is in the sequence because 6! + 2! + 0!  = 720 + 2 + 1 = 723, and sum of the divisors 1< d< n = sigma(620) - n - 1 = 1344 - 620 - 1 = 723.
		

Crossrefs

Programs

  • Maple
    isA202239 := proc(n)
            A061602(n) = A048050(n) ;
    end proc:
    for n from 1 do
            if isA202239(n) then
            print(n) ;
            end if;
    end do; # R. J. Mathar, Dec 18 2011
  • Mathematica
    Q[n_]:=Module[{a=Total[Rest[Most[Divisors[n]]]]}, a == Total[IntegerDigits[n]!]]; Select[Range[2, 10^8], Q]

Formula

{n: A061602(n)= A048050(n)}. - R. J. Mathar, Dec 18 2011

Extensions

a(17)-a(27) from Donovan Johnson, Jan 14 2012