1,2

Or, numbers n such that product of aliquot divisors of n is n^2.

A084110(a(n)) = 1, see also A084116. - Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), May 12 2003

If M(n) denotes the product of the divisors of n, then n is said to be k-multiplicatively perfect if M(n)=n^k. All such numbers are of the form p q^(k-1) or p^(2k-1). This statement is in Sandor's paper. Therfore all 2-multiplicatively perfect numbers are semiprime p*q or cubes p^3. - Walter A. Kehowski (wkehowski(AT)cox.net), Sep 13 2005

K. Ireland and M. Rosen, A Classical Introduction to Modern Number Theory. Springer-Verlag, NY, 1982, p. 19.

J. Sandor, On multiplicatively e-perfect numbers, J.Ineq.Pure Applied Math(JIPAM), 5(2004), no.4, article 114.

T. D. Noe, Table of n, a(n) for n=1..1000

J. Sandor, Multiplicatively perfect numbers, J. Ineq. Pure Appl. Math. 2(2001), no. 1, article 3, 6 pp.

Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics.

Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics.

1 together with A030513.

Divisors of 10 are 1,2,5,10 with product 100=10^2.

k:=2: MPL:=[]: for z from 1 to 1 do for n from 1 to 5000 do if convert(divisors(n), `*`) = n^k then MPL:=[op(MPL), n] fi od; od; MPL; (Kehowski)

Adjacent sequences: A007419 A007420 A007421 this_sequence A007423 A007424 A007425

Sequence in context: A120497 A036436 A036455 this_sequence A030513 A065858 A073582

nonn,nice,easy

njas

Some numbers were omitted - thanks to Erich Friedman (erich.friedman(AT)stetson.edu) for pointing this out.