A344602 Integers whose Hamming weight is triangular.

0, 1, 2, 4, 7, 8, 11, 13, 14, 16, 19, 21, 22, 25, 26, 28, 32, 35, 37, 38, 41, 42, 44, 49, 50, 52, 56, 63, 64, 67, 69, 70, 73, 74, 76, 81, 82, 84, 88, 95, 97, 98, 100, 104, 111, 112, 119, 123, 125, 126, 128, 131, 133, 134, 137, 138, 140, 145, 146, 148, 152, 159, 161

Offset: 1

Author

Michel Marcus, May 24 2021

Keywords

• nonn
• base

Links

• Alois P. Heinz, Table of n, a(n) for n = 1..20000

Crossrefs

Cf. A000120, A000217, A344603.

Programs

Maple

q:= n-> issqr(8*add(i, i=Bits[Split](n))+1):
select(q, [$0..200])[];  # Alois P. Heinz, May 24 2021

Mathematica

Select[Range[0, 200], IntegerQ @ Sqrt[8 * Plus @@ IntegerDigits[#, 2] + 1] &] (* Amiram Eldar, May 24 2021 *)

PARI

isok(n) = ispolygonal(hammingweight(n), 3);