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A076380 Sum of digits in base 2 is a divisor of sum of prime divisors (A008472). 7

%I #9 Jan 08 2019 17:07:42

%S 2,4,8,14,15,16,26,28,32,33,35,38,39,42,45,51,52,56,64,65,66,74,75,76,

%T 81,84,91,95,98,104,112,114,119,126,128,129,130,132,134,135,146,148,

%U 152,153,154,161,168,170,175,194,196,198,206,208,215,221,222,224,225

%N Sum of digits in base 2 is a divisor of sum of prime divisors (A008472).

%C Prime divisors counted without multiplicity. - _Harvey P. Dale_, Jan 08 2019

%H Harvey P. Dale, <a href="/A076380/b076380.txt">Table of n, a(n) for n = 0..1000</a>

%p A076380 := 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 2); t1 := floor(t1/2); 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[2,250],Divisible[Total[FactorInteger[#][[All,1]]],Total[ IntegerDigits[ #,2]]]&] (* _Harvey P. Dale_, Jan 08 2019 *)

%Y Cf. A075657, A076381 - A076387.

%K nonn,base

%O 0,1

%A _Floor van Lamoen_, Oct 08 2002

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Last modified April 19 10:38 EDT 2024. Contains 371791 sequences. (Running on oeis4.)