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A055682 a(n) = floor(n*sqrt(n)) - sigma(n), where sigma(n) is the sum of the divisors of n (A000203). 4
0, -1, 1, 1, 5, 2, 10, 7, 14, 13, 24, 13, 32, 28, 34, 33, 52, 37, 62, 47, 64, 67, 86, 57, 94, 90, 100, 92, 126, 92, 140, 118, 141, 144, 159, 125, 187, 174, 187, 162, 220, 176, 237, 207, 223, 239, 274, 208, 286, 260, 292, 276, 331, 276, 335, 299 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,5

COMMENTS

Always > 0 for n > 2.

REFERENCES

D. S. Mitrinovic et al., Handbook of Number Theory, Kluwer, Section III.1.1.b.

LINKS

Table of n, a(n) for n=1..56.

C. C. Lindner, Problem E1888, Amer. Math. Monthly, 73 (1966), 538; solution by A. Bager and S. Russ, op. cit. 74 (1967), 1143.

PROG

(PARI) a(n)=sqrtint(n^3)-sigma(n) \\ Charles R Greathouse IV, Feb 14 2013

CROSSREFS

Cf. A000203, A057641, A058208.

Sequence in context: A162396 A194046 A249368 * A187875 A136397 A065292

Adjacent sequences:  A055679 A055680 A055681 * A055683 A055684 A055685

KEYWORD

sign

AUTHOR

N. J. A. Sloane, Nov 29 2000

STATUS

approved

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Last modified October 21 02:22 EDT 2018. Contains 316405 sequences. (Running on oeis4.)