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A083657 a(n)=sum(i=1,n,floor(r*floor(r*i))) where r=sqrt(3). 0
1, 6, 14, 24, 37, 54, 74, 96, 121, 150, 182, 216, 254, 295, 338, 384, 434, 487, 542, 600, 662, 727, 794, 865, 939, 1016, 1095, 1178, 1264, 1352, 1443, 1538, 1636, 1736, 1839, 1946, 2056, 2168, 2284, 2403, 2525, 2649, 2777, 2908, 3041, 3177, 3317, 3460, 3605 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..49.

FORMULA

a(n) = (n/2)*(3n-1)+ n/sqrt(3) + O(1).

PROG

(PARI) a(n) = sum(i=1, n, floor(sqrt(3)*floor(sqrt(3)*i))); \\ Michel Marcus, Dec 05 2013

CROSSREFS

Sequence in context: A107400 A028557 A104675 * A228435 A317333 A010740

Adjacent sequences:  A083654 A083655 A083656 * A083658 A083659 A083660

KEYWORD

nonn

AUTHOR

Benoit Cloitre, Jun 13 2003

STATUS

approved

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Last modified December 5 15:11 EST 2019. Contains 329753 sequences. (Running on oeis4.)