OFFSET
1,1
EXAMPLE
34 is a term because (33 + 35)/2 = 34 = 2*17 is an even semiprime.
86 is a term because (85 + 87)/2 = 86 = 2*43 is an even semiprime.
MATHEMATICA
sp=Select[Range[5, 2400, 2], PrimeOmega[#]==2&]; a={}; For[i=1, i<Length[sp], i++, hav=Sum[Part[sp, k], {k, i, i+1}]/4; If[PrimeQ[hav], AppendTo[a, 2hav]]]; a (* Stefano Spezia, Aug 25 2023 *)
PROG
(PARI) upto(n) = {my(res = List(), l = List([0, 9]), s = sum(i = 1, #l, l[i]), i = l[#l]+2, ntimes2 = 2*n); while(1, if(bigomega(i) == 2, s += (i-l[1]); if(s > ntimes2, return(res)); if(s % 4 == 0 && isprime(s/4), listput(res, s/2)); listpop(l, 1); listput(l, i)); i+=2)} \\ David A. Corneth, Aug 26 2023
CROSSREFS
KEYWORD
nonn
AUTHOR
Elmo R. Oliveira, Aug 25 2023
STATUS
approved