OFFSET
1,1
COMMENTS
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
EXAMPLE
1800 is a term since A380845(18) = 5400 = 3 * 1800.
MATHEMATICA
q[k_] := Module[{h = DigitCount[k, 2, 1]}, DivisorSum[k, # &, DigitCount[#, 2, 1] == h &] == 3*k]; Select[Range[10^6], q]
PROG
(PARI) isok(k) = {my(h = hammingweight(k)); sumdiv(k, d, d*(hammingweight(d) == h)) == 3*k; }
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
Amiram Eldar, Feb 05 2025
STATUS
approved