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 A356423 #6 Oct 02 2022 00:53:55 %S A356423 57,145,177,1649,7073,23401,131361,423393,2012174,4785713,33555057, %T A356423 43050817,177264449,364568617,1073792449,4486784401,13877119009, %U A356423 31381070257,94143190994,125937424601,2552470327702,8796093024057,33233199005057,130291290501553,1628414210130481,1853020188884609 %N A356423 Leyland numbers which are products of two distinct primes. %C A356423 A squarefree subsequence of Leyland numbers (which are numbers that can be written as a^b + b^a for a, b > 1). %e A356423 57 = 3*19 = 5^2 + 2^5. %e A356423 2012174 = 2*1006087 = 9^5 + 5^9. %e A356423 4486784401 = 11*407889491 = 10^9 + 9^10. %e A356423 2552470327702 = 2*1276235163851 = 13^9 + 9^13. %Y A356423 Intersection of A076980 and A006881. %K A356423 nonn %O A356423 1,1 %A A356423 _Massimo Kofler_, Aug 07 2022