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 A192711 #7 Sep 04 2022 20:55:03 %S A192711 2,6,19,49,118,259,534,1042,1941,3465,5996,10040,16364,26012,40522, %T A192711 61835,92657,136556,198316,283977,401349,560438,774140,1058263, %U A192711 1432174,1920672,2554179,3369134,4409927,5730887,7397192,9486111,12090252,15318436 %N A192711 Number of 10 X 2 integer matrices with each row summing to zero, row elements in nondecreasing order, rows in lexicographically nondecreasing order, and the sum of squares of the elements <= 2*n^2 (number of collections of 10 zero-sum 2-vectors with total modulus squared not more than 2*n^2, ignoring vector and component permutations). %C A192711 Column (10,2,n) of A192710. %H A192711 R. H. Hardin, <a href="/A192711/b192711.txt">Table of n, a(n) for n = 1..86</a> %e A192711 Some solutions for 10 X 2 <= 2*4^2 %e A192711 .-2..2...-3..3...-2..2...-1..1....0..0...-2..2...-3..3...-1..1...-3..3...-2..2 %e A192711 .-1..1...-2..2...-2..2...-1..1....0..0...-2..2...-2..2....0..0...-1..1...-1..1 %e A192711 .-1..1...-1..1...-2..2...-1..1....0..0...-2..2...-1..1....0..0....0..0...-1..1 %e A192711 .-1..1...-1..1...-1..1....0..0....0..0...-1..1....0..0....0..0....0..0...-1..1 %e A192711 ..0..0...-1..1....0..0....0..0....0..0...-1..1....0..0....0..0....0..0...-1..1 %e A192711 ..0..0....0..0....0..0....0..0....0..0....0..0....0..0....0..0....0..0....0..0 %e A192711 ..0..0....0..0....0..0....0..0....0..0....0..0....0..0....0..0....0..0....0..0 %e A192711 ..0..0....0..0....0..0....0..0....0..0....0..0....0..0....0..0....0..0....0..0 %e A192711 ..0..0....0..0....0..0....0..0....0..0....0..0....0..0....0..0....0..0....0..0 %e A192711 ..0..0....0..0....0..0....0..0....0..0....0..0....0..0....0..0....0..0....0..0 %Y A192711 Cf. A192710. %K A192711 nonn %O A192711 1,1 %A A192711 _R. H. Hardin_, Jul 07 2011