OFFSET
1,1
COMMENTS
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
EXAMPLE
MATHEMATICA
sp=Select[Range[4, 1000], 2==PrimeOmega[#]&]; Select[Table[sp[[k]]+sp[[k+1]], {k, 100}], #==(p=NextPrime[#/2, -1])+NextPrime[p]&]
Module[{nn=2000, sp}, sp=Total/@Partition[Select[Range[nn], PrimeOmega[#]==2&], 2, 1]; Intersection[ sp, Total/@Partition[Prime[Range[nn]], 2, 1]]] (* Harvey P. Dale, Jul 31 2023 *)
PROG
(PARI) issemi(n)=bigomega(n)==2
nextsp(x)=x=ceil(x); while(!issemi(x), x++); x
has(n)=precprime((n-1)/2)+nextprime(n/2)==n
list(lim)=my(v=List(), last=4, t); forfactored(n=6, nextsp(lim\2), if(vecsum(n[2][, 2])==2, if(has(t=last+n[1]) && t<=lim, listput(v, t)); last=n[1])); Vec(v) \\ Charles R Greathouse IV, Feb 19 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov, Jun 20 2017
STATUS
approved