
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 7, 7, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 10, 10, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 13, 13, 13, 13, 14, 14, 15, 15, 15, 15, 15, 15, 16, 16, 17, 17, 17, 17, 18, 18, 18
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OFFSET

1,18


LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000
Marc Deléglise, Bounds for the density of abundant integers, Experiment. Math. Volume 7, Issue 2 (1998), 137143.
Charles R. Wall, Phillip L. Crews and Donald B. Johnson, Density bounds for the sum of divisors function, Math. Comp. 26 (1972), 773777.
Eric Weisstein's World of Mathematics, Abundant Number


MATHEMATICA

A091194[1]=0; A091194[n_]:=A091194[n]=A091194[n1]+Boole[DivisorSigma[1, n]>2n];
(* Recursive expression with data kept in memory; Enrique Pérez Herrero, Aug 14 2010 *)


PROG

(PARI) (n) = sum(k=1, n, sigma(k)/k > 2); \\ Michel Marcus, Apr 02 2015
(MAGMA) [#[k:k in [1..n] DivisorSigma(1, k) gt 2*k]:n in [1..90]]; // Marius A. Burtea, Nov 06 2019


CROSSREFS

Cf. A005101, A091195.
Sequence in context: A112751 A316843 A283297 * A156079 A268708 A061555
Adjacent sequences: A091191 A091192 A091193 * A091195 A091196 A091197


KEYWORD

nonn


AUTHOR

Reinhard Zumkeller, Dec 27 2003


STATUS

approved

