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 A127715 #17 Feb 15 2022 02:46:16 %S A127715 1,1,3,14,86,645,5662,56632,633545,7820115,105401961,1538517351, %T A127715 24157841308,405778641302,7256711524298,137607733327779, %U A127715 2757147167433326,58188668578629283,1289965088962987961 %N A127715 Rightmost border of triangle A127714: a(n) = A127714(n, (n+1)*(n+2)/2 - 1). %H A127715 Paul D. Hanna, <a href="/A127715/b127715.txt">Table of n, a(n), n = 0..100</a>. %F A127715 From _Gary W. Adamson_, Aug 02 2011: (Start) %F A127715 a(n) = upper left term of M^n, M is an infinite square production matrix in which nonzero terms = A033184 with the first "1" deleted, as follows: M = %F A127715 1, 1, 0, 0, 0, 0, ... %F A127715 2, 2, 1, 0, 0, 0, ... %F A127715 5, 5, 3, 1, 0, 0, ... %F A127715 14, 14, 9, 4, 1, 0, ... %F A127715 42, 42, 28, 14, 5, 1, ... %F A127715 ... (End) %e A127715 a(3) = 14 = the upper left term of M^3. %Y A127715 Cf. A127714, A127716, A033184 %K A127715 nonn %O A127715 0,3 %A A127715 _Paul D. Hanna_, Jan 24 2007