A320699 Numbers whose product of prime indices is a nonprime prime power (A246547).

7, 9, 14, 18, 19, 21, 23, 25, 27, 28, 36, 38, 42, 46, 49, 50, 53, 54, 56, 57, 63, 72, 76, 81, 84, 92, 97, 98, 100, 103, 106, 108, 112, 114, 115, 121, 125, 126, 131, 133, 144, 147, 152, 159, 162, 168, 171, 184, 189, 194, 196, 200, 206, 212, 216, 224, 227, 228

Offset: 1

Author

Gus Wiseman, Oct 19 2018

Keywords

• nonn

Comments

First differs from A320325 at a(43) = 152, A320325(43) = 151.

A prime index of n is a number m such that prime(m) divides n. The multiset of prime indices of n is row n of A112798.

Examples

			The sequence of all integer partitions whose Heinz numbers belong to the sequence begins: (4), (2,2), (4,1), (2,2,1), (8), (4,2), (9), (3,3), (2,2,2), (4,1,1), (2,2,1,1), (8,1), (4,2,1), (9,1), (4,4), (3,3,1), (16), (2,2,2,1), (4,1,1,1), (8,2), (4,2,2), (2,2,1,1,1), (8,1,1), (2,2,2,2), (4,2,1,1), (9,1,1), (25), (4,4,1), (3,3,1,1).
		

Links

• Index entries for sequences computed from indices in prime factorization

Crossrefs

Cf. A000720, A000961, A001597, A003963, A056239, A064573, A112798, A246547, A246655, A279787, A320322, A320325, A320698, A320700.

Programs

Mathematica

Select[Range[100],With[{x=Times@@Cases[FactorInteger[#],{p_,k_}:>PrimePi[p]^k]},!PrimeQ[x]&&PrimePowerQ[x]]&]