A156223 Numbers that are products of distinct terms in A000312.

1, 4, 27, 108, 256, 1024, 3125, 6912, 12500, 27648, 46656, 84375, 186624, 337500, 800000, 823543, 1259712, 3200000, 3294172, 5038848, 11943936, 16777216, 21600000, 22235661, 47775744, 67108864, 86400000, 88942644, 145800000, 210827008, 322486272, 387420489, 452984832

Offset

1,2

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Example

a(1) = 1 = 1^1.
a(2) = 4 = 2^2.
a(3) = 108 = 2^2 * 3^3.
...
a(20) = 5038848 = 2^2 * 3^3 * 6^6.

Mathematica

seq[max_] := Module[{kmax = 1, s = {1}}, While[kmax^kmax < max, kmax++]; Do[s = Select[Union[s, k^k*s], # <= max &], {k, 1, kmax}]; s]; seq[10^8] (* Amiram Eldar, Nov 24 2020 *)

Crossrefs

Cf. A000312.

Sequence in context: A071175 A352331 A063262 * A048102 A171469 A267685

Adjacent sequences: A156220 A156221 A156222 * A156224 A156225 A156226

Keyword

nonn

Author

Gabriel C. Benamy, Feb 06 2009

Extensions

More terms from Amiram Eldar, Nov 24 2020

Status

approved