A230357 Numbers n such that digit sum of n equals digit sum of sopf(n) (sum of the distinct prime factors of n).

22, 94, 105, 114, 136, 140, 160, 166, 202, 222, 234, 250, 265, 274, 346, 355, 361, 382, 424, 438, 445, 454, 516, 517, 526, 532, 562, 634, 702, 706, 712, 732, 812, 913, 915, 922, 1036, 1071, 1086, 1111, 1116, 1122, 1138, 1165, 1185, 1204, 1206, 1219, 1221, 1230, 1239, 1255, 1282, 1312, 1316, 1318, 1345, 1363, 1400, 1404, 1432, 1507, 1520, 1530, 1550

Offset: 1

Author

Antonio Roldán, Oct 16 2013

Keywords

• nonn
• base
• less

Examples

			166=2*83. Sopf(166)=85. Digit_sum(166)=13, digit_sum(85)=13.
		

Crossrefs

Cf. A006753, A036920, A230354, A230355, A230356.

Programs

PARI

sopf(n)= { local(f, s=0); f=factor(n); for(i=1, matsize(f)[1], s+=f[i, 1]); return(s) }
digsum(n)={local (d, p); d=0; p=n; while(p, d+=p%10; p=floor(p/10)); return(d)}
{for (n=4, 2*10^3,m=sopf(n);if(digsum(n)==digsum(m)&&m<>n,print(n)))}