OFFSET
1,1
MATHEMATICA
f[n_] := Length[Select[Range[10^n], PrimeQ[#] && PrimeQ[4#+1]&]]; Table[f[n], {n, 7}]
PROG
(PARI) a(n)=my(s=0); forprime(p=2, 10^n, s+=isprime(4*p+1)); s \\ Charles R Greathouse IV, Apr 23 2012
CROSSREFS
KEYWORD
nonn
AUTHOR
Enrique Pérez Herrero, Apr 22 2012
EXTENSIONS
a(10)-a(12) from Charles R Greathouse IV, Apr 23 2012
STATUS
approved