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 A344529 #17 Jun 28 2021 10:38:53 %S A344529 0,0,0,1,1,0,0,1,0,1,0,2,1,1,4,1,4,0,0,6,3,0,0,7,8,3,0,5,3,8,0,1,0,5, %T A344529 5,3,10,0,10,11,5,5,0,3,5,0,0,11,0,11,18,15,5,0,6,10,0,6,0,26,4,0,11, %U A344529 1,32,3,0,10,2,10,0,10,12,17,34 %N A344529 a(n) is the number of integer quadrilaterals (up to congruence) with integer side lengths a,b,c,d with n = Max(a,b,c,d), integer diagonals e,f and integer area. %C A344529 This sequence is the sum of the sequences A342721 and A342723 which deal with concave and convex quadrilaterals respectively. %F A344529 a(n) = A342721(n) + A342723(n). %e A344529 a(4)=1 because the smallest possible quadrilateral is a rectangle with a=c=4, b=d=3, e=f=5 and area 12. %Y A344529 Cf. A342720, A342721, A342722, A342723, A344528. %K A344529 nonn %O A344529 1,12 %A A344529 _Herbert Kociemba_, May 22 2021