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A066377 Number of numbers m <= n such that floor(sqrt(m)) divides m. 2
1, 3, 6, 10, 16, 24, 33, 45, 60, 76, 96, 120, 145, 175, 210, 246, 288, 336, 385, 441, 504, 568, 640, 720, 801, 891, 990, 1090, 1200, 1320, 1441, 1573, 1716, 1860, 2016, 2184, 2353, 2535, 2730, 2926, 3136, 3360, 3585, 3825, 4080, 4336 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Harry J. Smith, Table of n, a(n) for n=1,...,1000

FORMULA

Empirical G.f.: -x*(x^3-x^2-x-1) / ((x-1)^4*(x^2+x+1)^2). [Colin Barker, Jan 12 2013]

PROG

(PARI) { n=0; a=0; for (m=1, 10^9, if (m%floor(sqrt(m)) == 0, a+=m; write("b066377.txt", n++, " ", a); if (n==1000, return)) ) } [From Harry J. Smith, Feb 12 2010]

CROSSREFS

Partial sums of A006446.

Sequence in context: A088637 A256529 A256528 * A259823 A264847 A173653

Adjacent sequences:  A066374 A066375 A066376 * A066378 A066379 A066380

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Dec 23 2001

STATUS

approved

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Last modified May 25 21:41 EDT 2017. Contains 287059 sequences.