A288370 Primes of the form k!10 + 2, where k!10 is the decuple factorial number (A288327).

3, 5, 7, 11, 13, 41, 173, 233, 1877, 293603, 318482201, 3047775608243, 22045250515087152640289, 1302844523174285888671877, 930620100318118916029523201, 4831436058626442432403564453127, 2060356301148292483532951454058361, 9936127455089061347552058319626135203

Offset

1,1

Links

Robert Price, Table of n, a(n) for n = 1..29

Henri and Renaud Lifchitz, PRP Records.Search for n!10+2.

Joe McLean, Interesting Sources of Probable Primes.

OpenPFGW Project, Primality Tester.

Formula

a(n) = 2 + A288327(A204657(n+1)). - Elmo R. Oliveira, Feb 26 2025

Mathematica

MultiFactorial[n_, k_] := If[n<1, 1, n*MultiFactorial[n-k, k]];
Select[Table[MultiFactorial[i, 10] + 2, {i, 0, 100}], PrimeQ[#]&]

Crossrefs

Cf. A204657, A288327.

Sequence in context: A179739 A093988 A175914 * A108817 A288892 A373349

Adjacent sequences: A288367 A288368 A288369 * A288371 A288372 A288373

Keyword

nonn,changed

Author

Robert Price, Jun 08 2017

Status

approved