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 A281302 Largest nonnegative k such that binomial(2*c-1, c-1) == 1 (mod c^k), where c is the n-th composite number. 3
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 OFFSET 1 COMMENTS a(n) > 0 if c is either a term of A168363 or a term of A228562. If c is a term of A267824, then a(n) > 1. If there is a composite c that is a counterexample to the converse of Wolstenholme's theorem, that composite has a(i) > 2, where i is the index of c in A002808. LINKS Antti Karttunen, Table of n, a(n) for n = 1..25000 Wikipedia, Wolstenholme's theorem. PROG (PARI) forcomposite(c=1, , my(k=0); while(Mod(binomial(2*c-1, c-1), c^k)==1, k++); print1(k-1, ", ")) CROSSREFS Cf. A002808, A168363, A244919, A267824. Sequence in context: A194670 A130543 A193243 * A160753 A328981 A024360 Adjacent sequences:  A281299 A281300 A281301 * A281303 A281304 A281305 KEYWORD nonn AUTHOR Felix FrÃ¶hlich, Jan 21 2017 EXTENSIONS More terms from Antti Karttunen, Nov 08 2018 STATUS approved

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Last modified November 26 12:37 EST 2020. Contains 338639 sequences. (Running on oeis4.)