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 A073130 a(n) = gcd(p(n+1) - p(n), p(p(n+1)) - p(p(n))), where p(n) is the n-th prime. 3
 1, 2, 2, 2, 2, 2, 2, 4, 2, 2, 6, 2, 2, 4, 6, 6, 2, 6, 2, 2, 2, 2, 6, 8, 2, 2, 4, 2, 2, 2, 2, 2, 2, 2, 2, 6, 6, 4, 2, 2, 2, 2, 2, 2, 2, 4, 4, 4, 2, 4, 2, 2, 2, 6, 6, 6, 2, 2, 4, 2, 2, 2, 4, 2, 2, 2, 6, 2, 2, 2, 6, 4, 6, 6, 2, 6, 4, 2, 2, 2, 2, 2, 2, 6, 2, 6, 4, 2, 2, 4, 4, 2, 4, 2, 2, 2, 12, 2, 6, 2, 2, 2, 6, 2 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS G. C. Greubel, Table of n, a(n) for n = 1..1000 MAPLE seq(gcd(ithprime(n+1) - ithprime(n), ithprime(ithprime(n+1)) - ithprime(ithprime(n))), n=1..120); # G. C. Greubel, Oct 20 2019 MATHEMATICA Table[GCD[Prime[n+1]-Prime[n], Prime[Prime[n+1]]-Prime[Prime[n]]], {n, 120}] PROG (PARI) vector(120, n, gcd(prime(n+1) - prime(n), prime(prime(n+1)) - prime(prime(n))) ) \\ G. C. Greubel, Oct 20 2019 (MAGMA) [GCD(NthPrime(n+1) - NthPrime(n), NthPrime(NthPrime(n+1)) - NthPrime(NthPrime(n))): n in [1..120]]; // G. C. Greubel, Oct 20 2019 (Sage) [gcd(nth_prime(n+1) - nth_prime(n), nth_prime(nth_prime(n+1)) - nth_prime(nth_prime(n))) for n in (1..120)] # G. C. Greubel, Oct 20 2019 CROSSREFS Cf. A073131, A073132. Sequence in context: A100007 A104369 A051702 * A238267 A143526 A072924 Adjacent sequences:  A073127 A073128 A073129 * A073131 A073132 A073133 KEYWORD nonn AUTHOR Labos Elemer, Jul 16 2002 STATUS approved

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Last modified January 25 19:00 EST 2022. Contains 350572 sequences. (Running on oeis4.)