A230357 - OEIS

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

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OFFSET

1,1

LINKS

Table of n, a(n) for n=1..65.

EXAMPLE

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

PROG

(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)))}