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

1,1

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)))}

Crossrefs

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

Sequence in context: A041942 A231265 A041944 * A145769 A256152 A159539

Adjacent sequences: A230354 A230355 A230356 * A230358 A230359 A230360

Keyword

nonn,base,less

Author

Antonio Roldán, Oct 16 2013

Status

approved