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A064813 a(n) = binomial(composite(n), n), where composite = A002808, composite numbers. 1

%I #12 Jun 19 2018 05:12:02

%S 4,15,56,126,252,924,3432,6435,11440,43758,167960,293930,497420,

%T 1961256,3268760,5311735,8436285,13123110,54627300,225792840,

%U 354817320,548354040,834451800,1251677700,5414950296,8122425444,12033222880

%N a(n) = binomial(composite(n), n), where composite = A002808, composite numbers.

%H Harry J. Smith, <a href="/A064813/b064813.txt">Table of n, a(n) for n = 1..200</a>

%o (PARI)j=0; i=4; while(i<100, while(isprime(i),i=i+1); j=j+1; print(binomial(i,j)); i=i+1)

%o (PARI) nextComp(n)= { if (!isprime(n), return(n)); return(n + 1) } { c=3; for (n=1, 200, c=nextComp(c + 1); write("b064813.txt", n, " ", binomial(c, n)) ) } \\ _Harry J. Smith_, Sep 27 2009

%Y Cf. A002808, A060604.

%K nonn

%O 1,1

%A _Reinhard Zumkeller_, Oct 23 2001

%E More terms from _Matthew Conroy_, Oct 30 2001

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Last modified March 29 05:28 EDT 2024. Contains 371264 sequences. (Running on oeis4.)