A294028 Composite numbers k such that k | 1 - A078712(k).

49, 77, 121, 203, 319, 413, 679, 721, 749, 841, 869, 1057, 1211, 1351, 1393, 1397, 1441, 1639, 1687, 1757, 1769, 1883, 2167, 2189, 2219, 2359, 2429, 2581, 2651, 2761, 2959, 3031, 3073, 3101, 3227, 3409, 3437, 3485, 3487, 3563, 3899, 4037, 4039, 4109, 4279

Offset: 1

Author

Amiram Eldar, Oct 22 2017

Keywords

• nonn

Comments

A018187 (restricted Perrin pseudoprimes) is the intersection of A013998 (unrestricted Perrin pseudoprimes) with this sequence.

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000
• William Adams and Daniel Shanks, Strong primality tests that are not sufficient, Math. Comp. 39 (1982), 255-300.

Crossrefs

Cf. A001608, A013998, A018187, A078712.

Programs

Mathematica

a={}; b=-Drop[CoefficientList[Series[(2x+3)/(x^3-x-1), {x, 0, 10^4}], x] ,1];
Do[If[!PrimeQ[k]&&Divisible[b[[k]]+1,k],AppendTo[a,k]],{k, 2, Length[b]}]; a