A301523 Integers which can be partitioned into two distinct factorials. 0! and 1! are not considered distinct.

3, 7, 8, 25, 26, 30, 121, 122, 126, 144, 721, 722, 726, 744, 840, 5041, 5042, 5046, 5064, 5160, 5760, 40321, 40322, 40326, 40344, 40440, 41040, 45360, 362881, 362882, 362886, 362904, 363000, 363600, 367920, 403200, 3628801, 3628802, 3628806, 3628824, 3628920, 3629520, 3633840, 3669120, 3991680

Offset

1,1

Comments

Numbers of the form i! + j! where i > j > 0. - Altug Alkan, Mar 23 2018

Primes in this sequence are A088332(n) for n > 1.

Links

Seiichi Manyama, Table of n, a(n) for n = 1..10000

Example

    + |   1    2    6   24
  ----+--------------------
    1 |
    2 |   3;
    6 |   7,   8;
   24 |  25,  26,  30;
  120 | 121, 122, 126, 144;

Mathematica

Union[Total/@Subsets[Range[10]!, {2}]] (* Harvey P. Dale, Aug 25 2020 *)

Crossrefs

Cf. A000142, A001048, A038507, A059590, A088332, A301593.

Sequence in context: A037208 A102007 A152486 * A105756 A152057 A177689

Adjacent sequences: A301520 A301521 A301522 * A301524 A301525 A301526

Keyword

nonn

Author

Seiichi Manyama, Mar 23 2018

Status

approved