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 A070010 GCD of consecutive values of sum-of-proper divisors. 1
 1, 1, 1, 1, 1, 1, 1, 1, 4, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 11, 1, 1, 1, 6, 2, 1, 1, 1, 1, 1, 1, 1, 5, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 4, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 4, 1, 1, 1, 23, 1, 1, 1, 1, 3, 1, 1, 5, 25, 1, 1, 1, 1, 3, 1, 1, 1, 1 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,9 LINKS Antti Karttunen, Table of n, a(n) for n = 1..10000 FORMULA a(n) = gcd(A001065(n+1), A001065(n)). MATHEMATICA GCD[DivisorSigma[1, n+1]-(n+1), DivisorSigma[1, n]-n] PROG (PARI) A001065(n) = (sigma(n) - n); A070010(n) = gcd(A001065(n), A001065(1+n)); \\ Antti Karttunen, Oct 05 2017 CROSSREFS Cf. A000203, A001065; GCD of various consecutive function values: A048586, A057467, A058515, A060778, A060780, A069896. Sequence in context: A184101 A164561 A178764 * A293768 A046564 A046592 Adjacent sequences:  A070007 A070008 A070009 * A070011 A070012 A070013 KEYWORD nonn AUTHOR Labos Elemer, Apr 11 2002 STATUS approved

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Last modified October 15 21:17 EDT 2019. Contains 328038 sequences. (Running on oeis4.)