A230356 Nonsquare numbers n such that digit sum of n = digit sum of square part of n.

10, 18, 27, 40, 45, 54, 63, 72, 90, 108, 117, 126, 135, 153, 160, 162, 171, 180, 207, 216, 220, 234, 243, 250, 252, 261, 270, 304, 306, 315, 333, 342, 351, 360, 405, 414, 423, 432, 450, 490, 504, 513, 522, 531, 540, 603, 612, 621, 630, 640, 702, 711, 720, 801, 810, 931

Offset: 1

Author

Antonio Roldán, Oct 16 2013

Keywords

• nonn
• base
• less

Examples

			135 = 2^3*5. Square part of 135 is 9. Digit_sum(135) =9, digit_sum(9) = 9.
		

Crossrefs

Cf. A006753, A230354, A230355, A230357.

Programs

PARI

digsum(n)={local (d, p); d=0; p=n; while(p, d+=p%10; p=floor(p/10)); return(d)}
{for (n=2, 10^3,m=n/core(n);if(digsum(n)==digsum(m)&&m<>n,print(n)));}