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%I #5 Oct 01 2013 17:58:07
%S 0,0,0,0,0,6,7,19,41,5,8,14,20,28,1327,46,1,82,104,125,150,177,207,
%T 252,3,4,436,46741,52523,58764,0,7,986,1079,8,9,1529,11,1850,2038,13,
%U 2426,14,15,3143,625601,0,0,21,5018,1169257,5520,5809,26,27,29,30,8299,8741
%N Integer part of n#/((p-11)# 11#), where p=preceding prime to n.
%C 0# = 1# = 2 by convention.
%F n# = product of primes <= n. 0#=1#=2. n#/((p-r)# r#) is analogous to the number of combinations of n things taken r at a time: C(n, r) = n!/((n-r)! r!) where factorial ! is replaced by primorial # and n is replaced with the preceding prime to n.
%o (PARI) c(n,r) = { local(p); forprime(p=2,n, print1(floor(primorial(p)/primorial(p-r)/primorial(r)+.0)",") ) } primorial(n) = \ The product of primes <= n using the pari primelimit. { local(p1,x); if(n==0||n==1,return(2)); p1=1; forprime(x=2,n,p1*=x); return(p1) }
%K easy,nonn
%O 2,6
%A _Cino Hilliard_, Feb 25 2005
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