A257658 Primes of the form A060735(k) +- 1, where A060735 lists multiples of primorials (A002110) less than the next larger primorial.

2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 59, 61, 89, 149, 151, 179, 181, 211, 419, 421, 631, 839, 1049, 1051, 1259, 1471, 1889, 2099, 2309, 2311, 4621, 9239, 9241, 11549, 11551, 13859, 18481, 20789, 23099, 25409, 25411, 30029, 90089, 120121, 150151, 180179, 180181

Offset: 1

Author

James M. McCanney and Robert G. Wilson v, Jul 26 2015

Keywords

• nonn

Comments

After a(9), all terms are congruent to +-1 (mod 30).

More generally, for any primorial P (cf. A002110), all terms >= P-1 are congruent to +/- 1 (mod P).- This sequence is essentially the same as A087715. - M. F. Hasler, Jul 27 2015

Examples

			149 & 151 are in the sequence because they are primes +-1 from A060735(12) = 150. A term does not have to be a twin prime; those are found in A087732.
		

Links

• James M. McCanney and Robert G. Wilson v, Table of n, a(n) for n = 1..1013

Crossrefs

Cf. A060735, A087732, A002110.

Essentially the same as A087715.

Programs

Mathematica

f[n_] := Range[Prime[n + 1] - 1] Times @@ Prime@ Range@ n; Select[ Union@ Flatten@ Join[ Array[f, 6] - 1, Array[f, 7, 0] + 1], PrimeQ@# &]

Formula

Primes among the numbers produced from A060735 +/- 1.