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A230291 a(n) = Sum_{i=1..n} d(24*i+17) - Sum_{i=1..n} d(6*i+5), where d(n) = A000005(n). 1
0, 2, 2, 2, 0, 2, 4, 6, 6, 4, 4, 4, 6, 6, 6, 6, 10, 10, 10, 10, 10, 12, 10, 10, 8, 6, 12, 14, 16, 16, 16, 18, 16, 18, 16, 14, 16, 16, 16, 12, 18, 22, 22, 24, 20, 22, 22, 24, 22, 20, 22, 28, 26, 26, 26, 24, 26, 26, 26, 26, 24, 28, 30, 30, 30, 30, 34, 34, 36, 32, 32, 32, 34, 36, 32, 34, 36, 34, 34, 34, 36, 36, 40, 42 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..84.

Jorge Luis Cimadevilla Villacorta, Certain inequalities associated with the divisor function, Amer. Math. Monthly, 120 (2013), 832-837. (Shows that a(n) >= 0.)

MAPLE

See A230290.

PROG

(PARI) vector(100, n, sum(i=1, n, numdiv(24*i+17)) - sum(i=1, n, numdiv(6*i+5))) \\ Michel Marcus, Oct 09 2014

CROSSREFS

Cf. A000005, A230290-A230296.

Sequence in context: A264136 A274850 A215594 * A059288 A319109 A217670

Adjacent sequences:  A230288 A230289 A230290 * A230292 A230293 A230294

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Oct 17 2013

STATUS

approved

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Last modified October 17 00:17 EDT 2018. Contains 316275 sequences. (Running on oeis4.)