A325511 Numbers whose prime signature is that of a factorial number.

1, 2, 3, 5, 6, 7, 10, 11, 13, 14, 15, 17, 19, 21, 22, 23, 24, 26, 29, 31, 33, 34, 35, 37, 38, 39, 40, 41, 43, 46, 47, 51, 53, 54, 55, 56, 57, 58, 59, 61, 62, 65, 67, 69, 71, 73, 74, 77, 79, 82, 83, 85, 86, 87, 88, 89, 91, 93, 94, 95, 97, 101, 103, 104, 106

Offset

1,2

Comments

A181819(a(n)) belongs to A325508.

Links

Table of n, a(n) for n=1..65.

Example

The sequence of terms together with their prime indices begins:
   1: {}
   2: {1}
   3: {2}
   5: {3}
   6: {1,2}
   7: {4}
  10: {1,3}
  11: {5}
  13: {6}
  14: {1,4}
  15: {2,3}
  17: {7}
  19: {8}
  21: {2,4}
  22: {1,5}
  23: {9}
  24: {1,1,1,2}
  26: {1,6}
  29: {10}
  31: {11}

Mathematica

Select[Range[30], MemberQ[Table[Sort[Last/@FactorInteger[k!]], {k, #}], Sort[Last/@FactorInteger[#]]]&]

Crossrefs

Cf. A000142, A011371, A022559, A076934, A115627, A181819, A325272, A325276, A325508, A325509, A325510.

Sequence in context: A248792 A358976 A064594 * A240370 A193304 A333634

Adjacent sequences: A325508 A325509 A325510 * A325512 A325513 A325514

Keyword

nonn

Author

Gus Wiseman, May 08 2019

Status

approved