OFFSET
1,2
LINKS
Gareth A. Jones and Alexander K. Zvonkin, A number-theoretic problem concerning pseudo-real Riemann surfaces, arXiv:2401.00270 [math.NT], 2023. See Table 4 at page 13.
MATHEMATICA
a[n_] := Length[Select[Range[10^n-2], PrimeQ[#] && PrimeQ[#+2] && Mod[#, 4] == 1 &]]; Array[a, 10]
PROG
(PARI) lista(nmax) = {my(prev = 2, c = 0, pow = 10, n = 1, nm = nmax + 1); forprime(p = 3, , if(p > pow, print1(c, ", "); pow *= 10; n++; if(n == nm, break)); if(prev % 4 == 1 && p == prev + 2, c++); prev = p); } \\ Amiram Eldar, Jun 03 2024
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Stefano Spezia, Jan 13 2024
EXTENSIONS
a(11)-a(12) from Amiram Eldar, Jun 03 2024
STATUS
approved