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

Author

Seiichi Manyama, Mar 23 2018

Keywords

• nonn

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.

Examples

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

Links

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

Crossrefs

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

Programs

Mathematica

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