A334633 Numbers k of the form p_1^p_m * p_2^p_(m-1) * ... * p_(m-1)^p_2 * p_m^p_1 for increasing primes p_i.

1, 4, 27, 72, 800, 3125, 6272, 21600, 30375, 169344, 247808, 750141, 823543, 1384448, 6690816, 19600000, 37380096, 37879808, 189267968, 190512000, 235782657, 774400000, 1022754816, 1313046875, 2344190625, 3502727631, 4326400000, 4437573632, 5110235136, 118374400000

Offset

1,2

Comments

More common than prime(n)^prime(n) (i.e., A051674).

Links

Table of n, a(n) for n=1..30.

Shaun Alan Isherwood, Name for numbers of the form pj1^pjn*pj2^pjn-1...pjn-1^pj2*pjn^pj1, Math StackExchange question.

M.S.E. user Peter, Math StackExchange discussion about the above

Example

1 is the product of zero primes, 4=2^2, 27=3^3, 72=2^3*3^2, 800=2^5*5^2.

Crossrefs

Cf. A000312, A051674.

Sequence in context: A122406 A276372 A071837 * A266011 A015238 A298987

Adjacent sequences: A334630 A334631 A334632 * A334634 A334635 A334636

Keyword

nonn

Author

Shaun Alan Isherwood, Sep 10 2020

Extensions

Missing terms 19600000 and 2344190625 added, more terms from and offset changed to 1 by Jinyuan Wang, Sep 12 2020

Status

approved