A071541 - OEIS

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A071541

Number of k's less than or equal to 10^n such that there are middle divisors of k (A071090).

6, 43, 336, 2932, 26870, 252756, 2409731 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,1`
	MATHEMATICA	`f[n_] := Plus @@ Select[ Divisors[n], Sqrt[n/2] <= # < Sqrt[n*2] &]; s = 0; k = 0; Do[ While[k < 10^n, k++; If[ f[k] != 0, s++ ]]; Print[s], {n, 1, 7}]`
	CROSSREFS	`Cf. A071540.` `Sequence in context: A098665 A153397 A005786 * A146966 A090010 A176732` `Adjacent sequences: A071538 A071539 A071540 * A071542 A071543 A071544`
	KEYWORD	`nonn`
	AUTHOR	`Robert G. Wilson v (rgwv(AT)rgwv.com), May 31 2002`

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Last modified February 16 12:41 EST 2012. Contains 205909 sequences.