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A257056 Numbers k such that (# squares) < (# nonsquares) in the quarter-squares representation of k. 3

%I #8 Apr 15 2015 15:44:55

%S 2,6,8,12,14,15,20,22,23,30,32,33,42,44,45,48,56,58,59,62,63,72,74,75,

%T 78,79,80,89,90,92,93,96,97,98,108,110,112,113,116,117,118,129,132,

%U 134,135,138,139,140,143,152,156,158,159,162,163,164,167,168,177

%N Numbers k such that (# squares) < (# nonsquares) in the quarter-squares representation of k.

%C Every positive integer is a sum of at most four distinct quarter squares; see A257019. The sequences A257056, A257057, A257058 partition the nonnegative integers.

%H Clark Kimberling, <a href="/A257056/b257056.txt">Table of n, a(n) for n = 1..1000</a>

%e Quarter-square representations:

%e r(0) = 0

%e r(1) = 1

%e r(2) = 2, so that a(1) = 2

%e r(3) = 2 + 1

%e r(4) = 4

%e r(5) = 4 + 1

%e r(6) = 6, so that a(2) = 6

%t z = 400; b[n_] := Floor[(n + 1)^2/4]; bb = Table[b[n], {n, 0, 100}];

%t s[n_] := Table[b[n], {k, b[n + 1] - b[n]}];

%t h[1] = {1}; h[n_] := Join[h[n - 1], s[n]];

%t g = h[100]; r[0] = {0};

%t r[n_] := If[MemberQ[bb, n], {n}, Join[{g[[n]]}, r[n - g[[n]]]]];

%t u = Table[Length[r[n]], {n, 0, z}] (* A257023 *)

%t v = Table[Length[Intersection[r[n], Table[n^2, {n, 0, 1000}]]], {n, 0, z}] (* A257024 *)

%t -1 + Select[Range[0, z], 2 v[[#]] < u[[#]] &] (* A257056 *)

%t -1 + Select[Range[0, z], 2 v[[#]] == u[[#]] &] (* A257057 *)

%t -1 + Select[Range[0, z], 2 v[[#]] > u[[#]] &] (* A257058 *)

%Y Cf. A257019, A000290, A257057, A257058.

%K nonn,easy

%O 1,1

%A _Clark Kimberling_, Apr 15 2015

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Last modified April 24 22:17 EDT 2024. Contains 371964 sequences. (Running on oeis4.)