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

1,1

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

Formula

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

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 *)

Crossrefs

Sequence in context: A046694 A326255 A326256 * A138563 A327908 A092797

Adjacent sequences: A210474 A210475 A210476 * A210478 A210479 A210480

Keyword

nonn

Author

R. J. Mathar, Jan 23 2013

Status

approved