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 A088651 #10 Oct 19 2017 03:14:24 %S A088651 3,3,4,6,6,154770,2894220,2894220,407874180,214580145780, %T A088651 9448481062020,247236503934420,2545206711847800,18178612369988250180, %U A088651 53792264108455702830 %N A088651 a(n) = smallest number k such that rk-1 is prime for all r = 1 to n. %C A088651 Is the sequence finite? %H A088651 Carlos Rivera, <a href="http://www.primepuzzles.net/puzzles/puzz_379.htm">Problems & Puzzles</a>. %e A088651 a(5)=6 because 1*6-1, 2*6-1, 3*6-1, 4*6-1, 5*6-1 are all prime. %e A088651 a(11)=9448481062020 because all eleven numbers 1*9448481062020-1, 2*9448481062020-1,3*9448481062020-1,...,10*9448481062020-1 & 11*9448481062020-1 are prime and 9448481062020 is the smallest number with such property. %Y A088651 Cf. A088652, A125838, A125839, A088250, A101779. %K A088651 nonn %O A088651 1,1 %A A088651 _Amarnath Murthy_, Oct 29 2003 %E A088651 Corrected and extended by _Ray Chandler_, Nov 01 2003 %E A088651 More terms from _Don Reble_, Nov 23 2003 %E A088651 Entry revised by _N. J. A. Sloane_, Jan 05 2007 %E A088651 a(14)-a(15) from _Jens Kruse Andersen_, May 02 2008