A217709 Numbers of the form p^q^r, for p,q,r primes.

16, 81, 256, 512, 625, 2401, 6561, 14641, 19683, 28561, 83521, 130321, 279841, 390625, 707281, 923521, 1874161, 1953125, 2825761, 3418801, 4879681, 5764801, 7890481, 12117361, 13845841, 20151121, 25411681, 28398241, 33554432, 38950081, 40353607, 47458321

Offset: 1

Author

Jonathan Vos Post, Mar 20 2013

Keywords

• nonn
• easy

Comments

Subset of A217261. Sequence suggested by Kevin L. Schwartz in a Facebook discussion.

Examples

			a(1) = 2^2^2 = 16;
a(2) = 3^2^2 = 81;
a(3) = 2^2^3 = 256;
a(4) = 2^3^2 = 512;
a(5) = 5^2^2 = 625.
		

Crossrefs

Cf. A000040, A000961, A217261.

Extensions

More terms from Alois P. Heinz, Mar 20 2013