1,1

a(n) = the smallest squarefree number m of the form p*q with prime factors p and q = p^2 + n, or 0 if no such number exists; m = p^3 + p*n.

a(n) = 0 for numbers n from A232010.

Table of n, a(n) for n=1..63.

a(4) = 39 because 39 = 3 * 13 = 3 * (3^2 + 4).

Cf. A005117, A232010, A067775, A232012, A023200.

Sequence in context: A120969 A265374 A231032 * A137723 A256352 A255533

Adjacent sequences: A232006 A232007 A232008 * A232010 A232011 A232012

nonn

Jaroslav Krizek, Nov 20 2013

approved