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%I #11 Sep 08 2022 08:45:06
%S 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,
%T 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,
%U 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
%N a(n) = gcd(p(n+1) - p(n), p(p(n+1)) - p(p(n))), where p(n) is the n-th prime.
%H G. C. Greubel, <a href="/A073130/b073130.txt">Table of n, a(n) for n = 1..1000</a>
%p seq(gcd(ithprime(n+1) - ithprime(n), ithprime(ithprime(n+1)) - ithprime(ithprime(n))), n=1..120); # _G. C. Greubel_, Oct 20 2019
%t Table[GCD[Prime[n+1]-Prime[n], Prime[Prime[n+1]]-Prime[Prime[n]]], {n, 120}]
%o (PARI) vector(120, n, gcd(prime(n+1) - prime(n), prime(prime(n+1)) - prime(prime(n))) ) \\ _G. C. Greubel_, Oct 20 2019
%o (Magma) [GCD(NthPrime(n+1) - NthPrime(n), NthPrime(NthPrime(n+1)) - NthPrime(NthPrime(n))): n in [1..120]]; // _G. C. Greubel_, Oct 20 2019
%o (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
%Y Cf. A073131, A073132.
%K nonn
%O 1,2
%A _Labos Elemer_, Jul 16 2002
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