A076381 Numbers n such that sum of digits in base 3 is a divisor of sum of prime divisors (A008472).

2, 3, 4, 9, 25, 27, 30, 42, 51, 66, 78, 81, 84, 90, 105, 114, 126, 138, 141, 147, 153, 156, 159, 168, 170, 185, 186, 187, 198, 201, 220, 222, 228, 231, 234, 243, 245, 246, 252, 258, 264, 270, 276, 282, 290, 291, 294, 301, 312, 315, 322, 323, 325, 336, 340, 341

Offset

1,1

Links

Table of n, a(n) for n=1..56.

Maple

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;

Mathematica

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

Crossrefs

Cf. A075657, A076380 - A076387.

Sequence in context: A333431 A085612 A073915 * A282571 A063455 A001144

Adjacent sequences: A076378 A076379 A076380 * A076382 A076383 A076384

Keyword

nonn,base

Author

Floor van Lamoen, Oct 08 2002

Status

approved