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 A274568 #14 Jul 06 2016 00:33:09 %S A274568 2,0,2,3,7,2,3,2,9,2,3,13,2,7,3,2,15,2,3,19,2,9,3,7,2,21,2,3,27,2,13, %T A274568 3,2,7,9,2,3,33,2,15,3,2,7,2,3,37,2,9,19,3,13,2,39,2,3,7,49,2,21,3,2, %U A274568 9,15,2,3,7,2,3,2,13,27,51,2,3,55,2,7,9,3,19 %N A274568 Irregular triangle read by rows in which the n-th row (n>1) lists distinct "factors" of n for the sieve described in A262775. %C A274568 This sequence is analogous to the prime factors of n, but for the sifted set A262775. If n is equivalent to some term A262775(k) mod A262775(k+1), then row n will include the term A262775(k+1). Row 1 is zero. %H A274568 Max Barrentine, <a href="/A274568/b274568.txt">Rows n = 0..10000, flattened</a> %H A274568 Max Barrentine, <a href="/A274568/a274568.txt">Rows n = 0..10000.</a> %e A274568 Row 2 is 2,3 because 2==0 mod 2 and A262775(0)=0, A262775(1)=2, and 2==2 mod 3 and A262775(1)=2, A262775(2)=3. %Y A274568 Cf. A262775, A027748, A264940, A272565. %K A274568 nonn,tabf %O A274568 0,1 %A A274568 _Max Barrentine_, Jun 28 2016