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 A119621 Wolstenholme numbers A007406 ( numerator of Sum 1/k^2, k = 1..(p-1)/2 ) divided by prime p>3. 0
 1, 7, 479, 413, 63397, 514639, 10410343, 1411432849, 6620481151, 6454614084953, 421950627598601, 8222379104323, 3989306589962303, 443539778381788333, 148124338024667050948691, 143366612154851808752629 (list; graph; refs; listen; history; text; internal format)
 OFFSET 3,2 COMMENTS Wolstenholme numbers A007406(n) (numerator of Sum 1/k^2, k = 1..n) are divisible by prime p > 3 for n = (p-1)/2. a(n) = A007406((p-1)/2) / p, where p = Prime[n] > 3. LINKS FORMULA a(n) = numerator[ Sum[ 1/i^2, {i,1,(Prime[n]-1)/2} ] ] / Prime[n] for n > 3. EXAMPLE A007406(n) begins 1, 5, 49, 205, 5269, 5369, 266681, 1077749, 9778141,.. a(3) = A007406( (5-1)/2 ) / 5 = 1 a(4) = A007406( (7-1)/2 ) / 7 = 49 / 7 = 7 a(5) = A007406( (11-1)/2 ) / 11 = 5269 / 11 = 479 MATHEMATICA Table[Numerator[Sum[1/i^2, {i, 1, (Prime[n]-1)/2}]]/Prime[n], {n, 3, 25}] CROSSREFS Cf. A007406. Sequence in context: A261806 A332147 A278143 * A142734 A120773 A116167 Adjacent sequences:  A119618 A119619 A119620 * A119622 A119623 A119624 KEYWORD frac,nonn AUTHOR Alexander Adamchuk, Jun 07 2006 STATUS approved

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Last modified September 25 12:23 EDT 2020. Contains 337343 sequences. (Running on oeis4.)