A206224 - OEIS

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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

(list; graph; refs; listen; history; text; internal format)

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