A206224 Floor(n^2/4) appears 1+floor(n/2) times.

0, 0, 1, 1, 2, 2, 4, 4, 4, 6, 6, 6, 9, 9, 9, 9, 12, 12, 12, 12, 16, 16, 16, 16, 16, 20, 20, 20, 20, 20, 25, 25, 25, 25, 25, 25, 30, 30, 30, 30, 30, 30, 36, 36, 36, 36, 36, 36, 36, 42, 42, 42, 42, 42, 42, 42, 49, 49, 49, 49, 49, 49, 49, 49, 56, 56, 56, 56, 56

Offset

0,5

Links

Table of n, a(n) for n=0..68.

Formula

a(n) = floor((1/4)*(floor(sqrt(4*n+1))-1)^2)

= A002620(A055086(n))

= A002620(A000267(n)-1)

Maple

seq(floor((1/4)*(floor(sqrt(4*k+1))-1)^2), k=0..50)

Mathematica

Flatten[Table[Table[Floor[n^2/4], {1 + Floor[n/2]}], {n, 0, 20}]] (* T. D. Noe, Feb 07 2012 *)

Crossrefs

Cf. A002620, A055086, A000267.

Sequence in context: A085237 A279891 A110870 * A035114 A202103 A333787

Adjacent sequences: A206221 A206222 A206223 * A206225 A206226 A206227

Keyword

nonn

Author

Mircea Merca, Feb 05 2012

Status

approved