A089998 Smallest square with Hamming weight n (i.e., with exactly n 1's when written in binary).

0, 1, 9, 25, 169, 121, 441, 1521, 2025, 5625, 24025, 47089, 109561, 32761, 393129, 851929, 1540081, 6275025, 15327225, 27258841, 41925625, 127893481, 243204025, 385611769, 998244025, 1979449081, 4823441401, 12870221809, 34324602361

Offset

0,3

Comments

A000120(a(n)) = n.

Links

Donovan Johnson, Table of n, a(n) for n = 0..60

Formula

a(n) = A231897(n)^2. - Hugo Pfoertner, Dec 27 2022

Mathematica

a = Table[0, {30}]; Do[c = Count[IntegerDigits[n^2, 2], 1]; If[ a[[c + 1]] == 0, a[[c + 1]] = n^2; Print[c, " = ", n^2]], {n, 1, 360000}] (* Robert G. Wilson v, Dec 03 2003 *)
Join[{0}, With[{s=DigitCount[Range[400000]^2, 2, 1]}, Flatten[Table[ Position[ s, _?(#==n&), 1, 1], {n, 30}]]]^2] (* Harvey P. Dale, Mar 03 2013 *)

Crossrefs

Cf. A000290, A089999, A061712, A090001, A231897.

Sequence in context: A146373 A084605 A098773 * A014728 A372382 A223646

Adjacent sequences: A089995 A089996 A089997 * A089999 A090000 A090001

Keyword

nonn,base

Author

Reinhard Zumkeller, Nov 20 2003

Extensions

More terms from Robert G. Wilson v, Dec 03 2003

Offset corrected by Donovan Johnson, May 01 2012

Status

approved