A050258 -id:A050258 - cp's OEIS frontend

A338868 Number of triples of prime quadruples < 10^n.

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 3, 9, 28, 138, 613, 2799

Offset: 1

Hans H. Brüggemann, Nov 13 2020

Number of triples of prime quadruples with at most n digits. A triple of prime quadruples consists of three prime quadruples with a (minimal) distance of 120.

			For n=12 the a(12)=2 solutions are [(282005261771, 282005261773, 282005261777, 282005261779), (282005261801, 282005261803, 282005261807, 282005261809) , (282005261891, 282005261893, 282005261897, 282005261899)] and [(783976940441, 783976940443, 783976940447, 783976940449), (783976940471, 783976940473, 783976940477, 783976940479), (783976940531, 783976940533, 783976940537, 783976940539)].

J. Brüggemann, The first triples of prime quadruples. [broken link]
J. Brüggemann, Calculating prime quadruples, its twins, triples and quadruples. [broken link]

Cf. A050258, A338866.

a(18) corrected by Hans H. Brüggemann, May 16 2021

A215473 Number of prime quadruples with smallest member < 2^n.

Original entry on oeis.org

0, 0, 1, 2, 2, 2, 3, 4, 4, 5, 7, 10, 11, 16, 23, 28, 43, 62, 106, 177, 309, 483, 795, 1305, 2105, 3525, 5923, 10096, 17259, 30004

Offset: 1

Alex Ratushnyak, Aug 12 2012

nonn

Prime quadruples (A007530) are numbers n such that n, n+2, n+6, n+8 are all prime.

			a(3) = 1 because there is only one prime quadruple below 2^3, namely {5, 7, 11, 13}.
a(4) = 2 because there are two prime quadruples below 2^4: the aforementioned and {11, 13, 17, 19}.

Cf. A050258, similar definition but with powers of 10 instead of 2.
Cf. A007530, A014561, A112540.
Cf. A033843, A007053.

(* First run program for A007530 *) Table[Length[Select[A007530, # < 2^n &]], {n, 14}] (* Alonso del Arte, Aug 12 2012 *)

cp's OEIS Frontend

A338868 Number of triples of prime quadruples < 10^n.

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