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 A141455 #16 Apr 18 2022 22:35:11 %S A141455 0,1,0,1,2,1,2,3,0,1,2,3,4,1,2,3,5,0,1,2,3,4,5,6,1,2,3,5,7,1,2,3,4,5, %T A141455 7,8,1,2,3,5,7,9,0,1,2,3,4,5,6,7,8,9,10,1,2,3,5,7,11,0,1,2,3,4,5,6,7, %U A141455 8,9,10,11,12,1,2,3,5,7,9,11,13,1,2,3,4,5,7,8,11,13,14,1,2,3,5,7,9,11,13,15 %N A141455 Irregular triangle showing the set of all possible values of primes modulo n in row n. %H A141455 Michael De Vlieger, <a href="/A141455/b141455.txt">Table of n, a(n) for n = 2..10209</a> (rows n = 2..180, flattened) %F A141455 Row n = A027748(n) U A038566(n), writing n as 0 iff n is prime. - _Michael De Vlieger_, Apr 18 2022 %e A141455 Table begins:0, 1; %e A141455 0, 1, 2; %e A141455 1, 2, 3; %e A141455 0, 1, 2, 3, 4; %e A141455 1, 2, 3, 5; %e A141455 0, 1, 2, 3, 4, 5, 6; %e A141455 1, 2, 3, 5, 7; %e A141455 1, 2, 3, 4, 5, 7, 8; %e A141455 1, 2, 3, 5, 7, 9; %e A141455 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10; %e A141455 1, 2, 3, 5, 7, 11; %e A141455 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12; %e A141455 1, 2, 3, 5, 7, 9, 11, 13; %e A141455 1, 2, 3, 4, 5, 7, 8, 11, 13, 14; %e A141455 1, 2, 3, 5, 7, 9, 11, 13, 15; %e A141455 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16; %e A141455 1, 2, 3, 5, 7, 11, 13, 17; %e A141455 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18; %e A141455 1, 2, 3, 5, 7, 9, 11, 13, 17, 19; %t A141455 Table[Union[FactorInteger[n][[All, 1]] /. n -> 0, Select[Range[n - 1], CoprimeQ[n, #] &]], {n, 2, 15}] (* _Michael De Vlieger_, Apr 18 2022 *) %Y A141455 Cf. A057859 (row lengths), A039701 (row n=3), A039704 (row n=6), A027748, A038566. %K A141455 nonn,tabf %O A141455 2,5 %A A141455 _Roger L. Bagula_ and _Gary W. Adamson_, Aug 07 2008