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A087193 H(p)/p where p runs through the primes and H(k) is the k-th central hexanomial coefficient (A018901). 1

%I #8 Jan 08 2020 18:40:15

%S 3,9,156,3431,2280921,64092034,55747783602,1700642242677,

%T 1657887524047959,54732141299289779730,1783584256683646551447,

%U 63884853139612229737722392,71016623651822742997810429944,2380864745882038026563515929162,2701273375177028344436110369387929

%N H(p)/p where p runs through the primes and H(k) is the k-th central hexanomial coefficient (A018901).

%H Andrew Howroyd, <a href="/A087193/b087193.txt">Table of n, a(n) for n = 1..100</a>

%F a(n) = A018901(prime(n))/prime(n). - _Andrew Howroyd_, Jan 08 2020

%o (PARI) \\ here b(n) is A018901.

%o b(n) = {if(n==0, 1, sum(k=0, 5*n\12, (-1)^k*binomial(n,k)*binomial(n + 5*n\2 - 6*k - 1, n - 1)))}

%o a(n) = {my(p=prime(n)); b(p)/p} \\ _Andrew Howroyd_, Jan 08 2020

%Y Cf. A000040 (primes), A018901 (central hexanomials).

%K nonn

%O 1,1

%A _Benoit Cloitre_, Oct 19 2003

%E Terms a(13) and beyond from _Andrew Howroyd_, Jan 08 2020

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Last modified March 3 04:18 EST 2024. Contains 370499 sequences. (Running on oeis4.)