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a(n) = binomial(prime(n), phi(prime(n) + 1)).
0

%I #17 Aug 28 2024 12:00:14

%S 1,3,10,35,330,1716,12376,75582,490314,4292145,300540195,17672631900,

%T 7898654920,960566918220,1503232609098,64617565719070,109712808959985,

%U 232714176627630544,13413576695470557606,5300174441392685400,873065282167813104916,13146145590943010676030

%N a(n) = binomial(prime(n), phi(prime(n) + 1)).

%C This sequence is a pseudo-random subsequence of Pascal's triangle.

%F a(n) << 2^p/sqrt(p), where p = prime(n). - _Charles R Greathouse IV_, Aug 12 2024

%e a(4) = 35 because binomial(prime(4), phi(prime(4) + 1)) = binomial(7, phi(8)) = binomial(7, 4) = 35.

%t Map[Binomial[#, EulerPhi[# + 1]] &, Prime[Range[22]]] (* _Amiram Eldar_, Aug 13 2024 *)

%Y Cf. A007318, A008331.

%K nonn

%O 1,2

%A _Mike Jones_, Aug 12 2024