A210477 Product of adjacent primes with a gap of 6.

667, 1147, 2491, 3127, 4087, 5767, 7387, 17947, 23707, 25591, 28891, 30967, 55687, 64507, 67591, 70747, 75067, 111547, 126727, 136891, 141367, 148987, 190087, 198907, 256027, 295927, 313591, 320347, 329467, 348091, 355207, 364807, 372091, 422491, 430327, 462391, 532891

Offset: 1

Author

R. J. Mathar, Jan 23 2013

Keywords

• nonn

Comments

Subsequence of A111192.

Sum_{n>=1} 1/a(n) > 0.00405067912.

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Programs

Maple

A210477 := proc(n)
    A031924(n)*(A031924(n)+6) ;
end proc:
seq(A210477(n),n=1..100) ; # R. J. Mathar, Jan 23 2013

Mathematica

Times@@@Select[Partition[Prime[Range[200]],2,1],#[[2]]-#[[1]]==6&] (* Harvey P. Dale, Aug 22 2019 *)

Formula

a(n) = A031924(n)*(A031924(n)+6).