OFFSET
1,2
LINKS
Eric Weisstein's World of Mathematics, Centered Square Number
EXAMPLE
221 is the smallest centered square number with binary weight 6 (221_10 = 11011101_2), so a(6) = 221.
MATHEMATICA
seq[len_, nmax_] := Module[{s = Table[0, {len}], n = 0, c = 0, bw, cs}, While[c < len && n < nmax, bw = DigitCount[cs = 2*n*(n+1) + 1, 2, 1]; If[bw <= len && s[[bw]] == 0, c++; s[[bw]] = cs]; n++]; s]; seq[30, 10^6] (* Amiram Eldar, Dec 26 2022 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Ilya Gutkovskiy, Dec 25 2022
STATUS
approved