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%I #12 Mar 05 2017 14:46:20
%S 39,94,106,118,146,158,185,201,221,254,302,365,427,473,485,519,537,
%T 589,633,655,707,723,749,767,842,851,869,901,1003,1145,1205,1211,1219,
%U 1247,1263,1337,1349,1603,1646,1681,1703,1731,1797,1891,1903,1937,2005,2019
%N Semiprimes that are the sum of four successive semiprimes.
%H Zak Seidov, <a href="/A158339/b158339.txt">Table of n, a(n) for n = 1..100000</a>
%e a(1)=39=6+9+10+14, or A001358(15)=A001358(2)+A001358(3)+A001358(4)+A001358(5).
%t Select[Total/@Partition[Select[Range[600],PrimeOmega[#]==2&],4,1], PrimeOmega[ #]==2&] (* _Harvey P. Dale_, Aug 14 2014 *)
%o (PARI) issemi(n)=bigomega(n)==2
%o list(lim)=if(lim<39, return([])); my(v=List(), u=v, x=lim\4+log(lim)*4\1+9); forprime(p=2,x\2, forprime(q=2,min(x\p,p), listput(u,p*q))); u=Set(u); while(u[#u-2]+u[#u-1]+u[#u]+x+1<=lim, while(!issemi(x++),); u=concat(u,x)); for(i=1,#u-3, u[i]+=u[i+1]+u[i+2]+u[i+3]); u[#u-2]=u[#u-1]=u[#u]=1; forprime(p=2,lim\2, forprime(q=2,min(lim\p,p), listput(v,p*q))); setintersect(Set(v), u) \\ _Charles R Greathouse IV_, Mar 05 2017
%Y Semiprimes that are the sum of k successive semiprimes: A131610 (k=3), A092192 (k=2), A001358 (k=1).
%K nonn
%O 1,1
%A _Zak Seidov_, Mar 16 2009
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