A203015 Primes p such that p + 1 or p - 1 is in A066120.

2, 3, 23, 8641, 653184001, 1601591599167888308924824752807936000000000000001

Offset

1,1

Comments

What is the next prime? As of January 2012, there are no known primes ending in 9 with this property.

Links

Table of n, a(n) for n=1..6.

G. L. Honaker, Jr. and Chris Caldwell, Prime Curios! 8641

Formula

a(n) are the prime values of p(0)# * (p(0)# * p(1)#) * (p(0)# * p(1)# * p(2)#) * (p(0)# * p(1)# * p(2)# * ... * p(n)#) +/- 1.

Example

A002110(1)^3*A002110(2)^2*A002110(3) + 1 = 8641, which is prime.

Mathematica

Select[Flatten[Table[Product[Product[Product[Prime[i], {i, j}], {j, k}], {k, n}] - 1 + m, {n, 0, 7}, {m, 0, 2, 2}]], PrimeQ]

Crossrefs

Cf. A066120, A002110.

Sequence in context: A076530 A360225 A238265 * A260420 A241661 A260071

Adjacent sequences: A203012 A203013 A203014 * A203016 A203017 A203018

Keyword

hard,nonn

Author

Arkadiusz Wesolowski, Jan 06 2012

Status

approved