A338944 Rearrangement of primes into complete Cunningham chains of the second kind, sorted by first prime in the chain.

2, 3, 5, 7, 13, 11, 17, 19, 37, 73, 23, 29, 31, 61, 41, 43, 47, 53, 59, 67, 71, 79, 157, 313, 83, 89, 97, 193, 101, 103, 107, 109, 113, 127, 131, 137, 139, 277, 149, 151, 163, 167, 173, 179, 181, 191, 197, 199, 397, 211, 421, 223, 227, 229, 457, 233, 239, 241

Offset

1,1

Comments

Analogous to A075712 but pertaining instead to primes of the form found in A005382.

Links

Michael De Vlieger, Table of n, a(n) for n = 1..10000

Chris K. Caldwell, Cunningham Chain (PrimePages, Prime Glossary).

Wikipedia, Cunningham chain.

Example

Triangle begins:
2, 3, 5;
7, 13;
11;
17;
19, 37, 73;
23;
29;
31, 61;
41;
...

Mathematica

Block[{a = {2}, j = 1, k, p}, Do[k = j; If[PrimeQ@ a[[-1]], AppendTo[a, 2 a[[-1]] - 1], While[! FreeQ[a, Set[p, Prime[k]]], k++]; j++; Set[a, Append[a[[1 ;; -2]], p]]], 10^3]; a]

Crossrefs

Cf. A005382, A075712, A338946.

Sequence in context: A332806 A108546 A065107 * A351528 A185956 A316885

Adjacent sequences: A338941 A338942 A338943 * A338945 A338946 A338947

Keyword

nonn,tabf

Author

Michael De Vlieger, Nov 17 2020

Status

approved