A076381 - OEIS

%I #8 Jul 09 2018 13:17:11

%S 2,3,4,9,25,27,30,42,51,66,78,81,84,90,105,114,126,138,141,147,153,

%T 156,159,168,170,185,186,187,198,201,220,222,228,231,234,243,245,246,

%U 252,258,264,270,276,282,290,291,294,301,312,315,322,323,325,336,340,341

%N Numbers n such that sum of digits in base 3 is a divisor of sum of prime divisors (A008472).

%p A076381 := proc(n) local i,j,t,t1, sod, sopd; t := NULL; for i from 2 to n do t1 := i; sod := 0; while t1 <> 0 do sod := sod + (t1 mod 3); t1 := floor(t1/3); od; sopd := 0; j := 1; while ithprime(j) <= i do if i mod ithprime(j) = 0 then sopd := sopd+ithprime(j); fi; j := j+1; od; if sopd mod sod = 0 then t := t,i; fi; od; t; end;

%t Select[Range[2,400],Divisible[Total[FactorInteger[#][[All,1]]],Total[ IntegerDigits[ #,3]]]&] (* _Harvey P. Dale_, Jul 09 2018 *)

%Y Cf. A075657, A076380 - A076387.

%K nonn,base

%O 1,1

%A _Floor van Lamoen_, Oct 08 2002