id:A111631 - OEIS Search Results

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Inverse of A110412 or zero if none exists.

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1, 2, 3, 5, 4, 17, 13, 6, 9, 8, 14, 0, 22, 26, 15, 401, 21, 12, 16, 0, 18, 20, 77, 226, 28, 65, 44, 626, 52, 32, 50, 125, 91, 24, 221, 404, 212, 42, 81, 45, 63, 40, 75, 66, 36, 56, 64, 338, 88, 104, 130, 153, 154, 152, 190, 328, 175, 48, 184, 245, 286, 182, 100, 105, 243 (list; graph; listen)

	OFFSET	`0,2`
	COMMENT	`A110412: Sum_{d<n is a divisor of n} tau(n-d).` `Found zeros < 7500 only for 12 & 20.`
	MATHEMATICA	`f[n_] := Plus @@ (DivisorSigma[0, n - # ] & /@ Most[Divisors[n]]); t = Table[0, {100}]; Do[a = f[n]; If[a < 100 && t[[a + 1]] == 0, t[[a + 1]] = n; Print[{a, n}]], {n, 630}]`
	CROSSREFS	`Cf. A110412.` `Sequence in context: A119745 A095753 A139537 this_sequence A118141 A082876 A096099` `Adjacent sequences: A111628 A111629 A111630 this_sequence A111632 A111633 A111634`
	KEYWORD	`nonn`
	AUTHOR	`Amarnath Murthy (amarnath_murthy(AT)yahoo.com) and Robert G. Wilson v (rgwv(AT)rgwv.com), Aug 09 2005`

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Last modified December 10 00:48 EST 2009. Contains 170565 sequences.

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