OFFSET
1,1
MATHEMATICA
cpQ[{a_, b_, c_, d_}]:=AllTrue[{2a+3, 2b+5, 2c+7, 2d+9}, PrimeQ] && NextPrime[ 2a+3] == 2b+5 && NextPrime[ 2b+5] == 2c+7 && NextPrime[ 2c+7] == 2d+9; PrimePi/@ Transpose[Select[ Partition[Prime[Range[ 1100000]], 4, 1], cpQ]][[1]] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Aug 14 2015 *)
PROG
(PARI) lista(nn) = {my(k=1, v=[2, 3, 5, 7]); forprime(p=11, nn, k++; v=concat(v[2..4], p); if(ispseudoprime(2*v[1]+3) && nextprime(2*v[1]+4)==2*v[2]+5 && nextprime(2*v[2]+6)==2*v[3]+7 && nextprime(2*v[3]+8)==2*v[4]+9, print1(k, ", "))); } \\ Jinyuan Wang, Mar 05 2020
CROSSREFS
KEYWORD
nonn
AUTHOR
Pierre CAMI, Feb 19 2005
EXTENSIONS
More terms from Harvey P. Dale, Aug 14 2015
STATUS
approved