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 A236434 #7 Jul 14 2015 00:08:18 %S A236434 2,3,5,2,3,11,13,2,3,7,41,2,3,11,17,59,2,3,11,23,31,47057,2,3,7,43, %T A236434 3041,4447,2,3,7,59,163,1381,775807,2,3,7,71,103,67213,713863,2,3,7, %U A236434 71,103,61559,29133437,2,3,11,23,31,47137,28282147,3892535183,2,3,11,23,31,47059,2259696349,110725121051,2,3,7,43,1831,138683,2861051,1456230512169437 %N A236434 Table whose n-th row lists the prime factors of the n-th Giuga number A007850(n). %C A236434 It is unknown whether there are infinitely many Giuga numbers or any odd ones. %C A236434 See A007850 for other comments, references, links, etc. %C A236434 For prime factors of primary pseudoperfect numbers, see A236433; of terms in Sylvester's sequence, see A126263. %H A236434 M. F. Hasler, <a href="/A236434/b236434.txt">Table of n, a(n) for n = 1..73</a> %e A236434 30 = 2 * 3 * 5. %e A236434 858 = 2 * 3 * 11 * 13. %e A236434 1722 = 2 * 3 * 7 * 41. %e A236434 66198 = 2 * 3 * 11 * 17 * 59. %e A236434 2214408306 = 2 * 3 * 11 * 23 * 31 * 47057. %e A236434 24423128562 = 2 * 3 * 7 * 43 * 3041 * 4447. %e A236434 432749205173838 = 2 * 3 * 7 * 59 * 163 * 1381 * 775807. %e A236434 14737133470010574 = 2 * 3 * 7 * 71 * 103 * 67213 * 713863. %e A236434 550843391309130318 = 2 * 3 * 7 * 71 * 103 * 61559 * 29133437. %e A236434 244197000982499715087866346 = 2 * 3 * 11 * 23 * 31 * 47137 * 28282147 * 3892535183. %e A236434 554079914617070801288578559178 = 2 * 3 * 11 * 23 * 31 * 47059 * 2259696349 * 110725121051. %e A236434 1910667181420507984555759916338506 = 2 * 3 * 7 * 43 * 1831 * 138683 * 2861051 * 1456230512169437. %e A236434 Another Giuga number (but possibly not the 13th) is 4200017949707747062038711509670656632404195753751630609228764416142557211582098432545190323474818 = 2 * 3 * 11 * 23 * 31 * 47059 * 2217342227 * 1729101023519 * 8491659218261819498490029296021 * 58254480569119734123541298976556403. %Y A236434 Cf. A007850, A216823, A216824, A236433. %K A236434 nonn,tabf,hard %O A236434 1,1 %A A236434 _Jonathan Sondow_, Jan 25 2014