This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A257658 #22 Aug 18 2015 12:55:16 %S A257658 2,3,5,7,11,13,17,19,23,29,31,59,61,89,149,151,179,181,211,419,421, %T A257658 631,839,1049,1051,1259,1471,1889,2099,2309,2311,4621,9239,9241,11549, %U A257658 11551,13859,18481,20789,23099,25409,25411,30029,90089,120121,150151,180179,180181 %N A257658 Primes of the form A060735(k) +- 1, where A060735 lists multiples of primorials (A002110) less than the next larger primorial. %C A257658 After a(9), all terms are congruent to +-1 (mod 30). %C A257658 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 %H A257658 James M. McCanney and Robert G. Wilson v, <a href="/A257658/b257658.txt">Table of n, a(n) for n = 1..1013</a> %F A257658 Primes among the numbers produced from A060735 +/- 1. %e A257658 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. %t A257658 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@# &] %Y A257658 Cf. A060735, A087732, A002110. %Y A257658 Essentially the same as A087715. %K A257658 nonn %O A257658 1,1 %A A257658 James M. McCanney and _Robert G. Wilson v_, Jul 26 2015