%I
%S 0,0,0,0,1,4,11,19,35,3,4,5,7,310,394,11,14,17,19,22,1653,27,31,35,0,
%T 46,4805,5300,5720,6275,0,79,85,90,0,107,112,121,129,137,147,154,0,
%U 175,34581,36029,1,1,241,55200,57676,265,274,1,307,321,336,347,357,370
%N Integer part of n#/((p7)# 7#), where p=preceding prime to n.
%C 0# = 1# = 2 by convention.
%F n# = product of primes <= n. 0#=1#=2. n#/((pr)# r#) is analogous to the number of combinations of n things taken r at a time: C(n, r) = n!/((nr)! 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(pr)/primorial(r)+.0)",") ) } primorial(n) = \ The product of primes <= n using the pari primelimit. { local(p1,x); if(n==0n==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
