login
Numbers such that the product of their digits is equal to 10 times the sum of their prime factors, without multiplicity.
0

%I #11 Feb 20 2019 15:09:37

%S 1584,5616,7452,8256,15698,16956,18525,25662,28512,34935,35152,35275,

%T 35581,35748,36584,46225,47265,47594,51842,52374,54479,55223,55348,

%U 58432,65712,73125,93875,118465,151632,153615,154462,159712,161785,172577,176225,178754,182596

%N Numbers such that the product of their digits is equal to 10 times the sum of their prime factors, without multiplicity.

%C Similar to Rhonda numbers (A099542) where the multiplicity of the prime factors is taken into account.

%e 1584 = 2^4*3^2*11 and 1*5*8*4 = 160 = 10*(2+3+11).

%p with(numtheory): select(n->convert(convert(n,base,10),`*`)=10*add(k,k=factorset(n)),[$1..120000]);

%t Select[Range[2*10^5], Times @@ IntegerDigits[#] == 10 Total[FactorInteger[#][[All, 1]] ] &] (* _Michael De Vlieger_, Feb 15 2019 *)

%Y Cf. A099542.

%K nonn,base,easy

%O 1,1

%A _Paolo P. Lava_, Feb 06 2019