A334542 Numbers m such that m^2 = p^2 + k^2, with p > 0, where p = A007954(m) = the product of digits of m.

1, 2, 3, 4, 5, 6, 7, 8, 9, 58, 85, 375, 666, 1968, 1998, 3578, 3665, 3891, 4658, 4995, 6675, 7735, 18434, 27475, 28784, 46692, 56763, 58896, 59577, 59949, 76965, 186633, 186673, 795848, 949968, 965667, 1339575, 1587616, 1929798, 2765388, 2989584, 3674195, 4763568, 5762784, 36741656, 58988961, 134369685, 188959392

Offset: 1

Author

Scott R. Shannon, May 05 2020

Keywords

• nonn
• base

Examples

			58 is a term as p = 5*8 = 40 and 58^2 = 3364 = 40^2 + 42^2.
3891 is a term as p = 3*8*9*1 = 216 and 3891^2 = 15139881 = 216^2 + 3885^2.
		

Links

• Giovanni Resta, Table of n, a(n) for n = 1..140 (terms < 2*10^13)

Crossrefs

Cf. A007954, A000404, A078134, A334557, A334558.

Subsequence of A052382 (zeroless numbers).

Programs

PARI

isok(m) = my(p=vecprod(digits(m))); p && issquare(m^2 - p^2); \\ Michel Marcus, May 06 2020