A104062 Number of primes p(i) for i=1 to 20*10^n such that p(i+1)=p(i)+6 and p(i+2)=p(i)+12 and p(i+3)=p(i)+18, 4 consecutive primes in arithmetic progression 0 6 12 18.

1, 12, 64, 416, 2748, 19348

Offset

1,2

Links

Table of n, a(n) for n=1..6.

Example

for i=1 to 20*10^1 (200) only one prime p(54)=251
251,257,263,269 consecutive primes in arithmetic progression 0,6,12,18
for i=1 to 20*10^2 (2000) 12 primes in arithmetic progression 0,6,12,18
for i=1 to 20*10^3 (20000) 64 primes in arithmetic progression 0,6,12,18

Mathematica

Table[Length[Select[Partition[Prime[Range[20*10^n]], 4, 1], Differences[#]=={6, 6, 6}&]], {n, 6}] (* Harvey P. Dale, Nov 03 2024 *)

Crossrefs

Sequence in context: A380353 A074359 A391894 * A371558 A232383 A003868

Adjacent sequences: A104059 A104060 A104061 * A104063 A104064 A104065

Keyword

more,nonn

Author

Pierre CAMI, Mar 02 2005

Extensions

Definition clarified by Harvey P. Dale, Jul 01 2015

Status

approved