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%I #10 Feb 14 2018 13:00:28
%S 3,3,5,1,4,1,2,4,1,1,5,2,4,1,1,2,2,3,2,4,1,1,13,2,1,1,2,2,4,3,6,2,1,1,
%T 1,3,6,1,1,3,5,2,2,7,2,1,2,6,1,4,1,3,4,6,1,7,1,1,2,2,2,1,6,2,1,2,4,4,
%U 1,2,2,2,4,1,14,6,1,3,2,2,5,1,13,2,1,1,1,2,4,14,1,2,1,1,1,3,4,4,5,2
%N a(n) is the number of consecutive integers starting with n summing up to a semiprime.
%H Harvey P. Dale, <a href="/A109824/b109824.txt">Table of n, a(n) for n = 1..10000</a>
%F A109824(n) = A109823(n) - n + 1.
%t Table[Position[Accumulate[Range[n,n+300]],_?(PrimeOmega[#]==2&),1,1],{n,100}]//Flatten (* The parameter 300 is sufficient for n up to 100000 but might have to be increased for larger n. *) (* _Harvey P. Dale_, Feb 14 2018 *)
%o (PARI) { a(n) = my(s, m); s=n; m=n; while(bigomega(s)!=2, m++; s+=m); m-n+1 }
%Y Cf. A109411, A109823.
%K nonn
%O 1,1
%A _Zak Seidov_ & _Max Alekseyev_, Jul 03 2005
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