A048599 Partial products of the sequence (A001097) of twin primes.

1, 3, 15, 105, 1155, 15015, 255255, 4849845, 140645505, 4360010655, 178760436855, 7686698784765, 453515228301135, 27664428926369235, 1964174453772215685, 143384735125371745005, 14481858247662546245505

Offset

0,2

Links

Table of n, a(n) for n=0..16.

Example

a(0) = 1 by the usual convention for an empty product. - N. J. A. Sloane, Feb 15 2024
a(5) = 15015 because 3 * 5 * 7 * 11 * 13 = 15015.

Mathematica

nextTwin[{list_, q_}] := Module[{p=NextPrime[q]}, {Join[list, If[PrimeQ[p-2]||PrimeQ[p+2], {p}, {}]], p}]
a001097[n_] := First[NestWhile[nextTwin, {{3}, 3}, Length[First[nextTwin[#]]]<=n&]]
a048599[n_] := FoldList[Times, 1, a001097[n]]
a048599[16] (* Hartmut F. W. Hoft, Apr 27 2021 *)
Join[{1}, FoldList[Times, Union[Flatten[Select[Partition[Prime[Range[30]], 2, 1], #[[2]]-#[[1]]==2&]]]]] (* Harvey P. Dale, Feb 15 2024 *)

Crossrefs

Cf. A048598, A001097.

Sequence in context: A354218 A118750 A070826 * A129731 A269455 A088109

Adjacent sequences: A048596 A048597 A048598 * A048600 A048601 A048602

Keyword

easy,nonn

Author

Den Roussel (DenRoussel(AT)webtv.net)

Extensions

More terms from Michael Lugo (mlugo(AT)thelabelguy.com), Dec 22 1999

Status

approved