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 A114531 #7 Mar 01 2019 02:59:55 %S A114531 1,2,16,214,2856,33367,349895,3302046,28597720,229893484,1730841042, %T A114531 12296287989,82945782429,533994100001,3295058878301,19560004053448, %U A114531 112049953456910,621112646095769,3339451666010949,17451533356424837,88807504851447189,440798078343276894 %N A114531 Number of intersections of a convex set with the n X n grid. %C A114531 This is a generalization of A114043, which can be viewed as the number of intersections of a halfspace with the n X n grid (divided by 2). %H A114531 Peter J. Taylor, <a href="/A114531/a114531.py.txt">Python program to generate terms</a> %e A114531 a(3) = 214 (X's indicate points in intersection): %e A114531 ... X.. .X. ... XX. X.. X.. X.. XXX XX. XX. XX. X.. X.. .X. .X. %e A114531 ... ... ... .X. ... .X. ..X ... ... X.. .X. ..X .XX .X. .X. XX. %e A114531 ... ... ... ... ... ... ... .X. ... ... ... ... ... ..X .X. ... %e A114531 -1- -4- -4- -1- -8- -4- -8- -8- -4- -4- -8- -8- -8- -2- -2- -4- %e A114531 XXX XXX XX. XX. XX. XX. .X. X.. XXX XXX XX. XX. XX. XX. .X. XX. %e A114531 X.. .X. XX. .X. .XX .X. XXX .XX XX. .X. .XX .XX XXX XX. XXX .X. %e A114531 ... ... ... .X. ... ..X ... .X. ... .X. ..X .X. ... ..X .X. .XX %e A114531 -8- -4- -4- -8- -8- -8- -4- -4- -8- -4- -4- -8- -8- -4- -1- -4- %e A114531 XXX XXX XXX XX. XX. XXX XXX XX. XXX XXX %e A114531 XXX XX. XX. XXX XXX XXX XXX XXX XXX XXX %e A114531 ... X.. .X. .X. ..X X.. .X. .XX XX. XXX %e A114531 -4- -4- -8- -4- -8- -8- -4- -2- -4- -1- %Y A114531 Cf. A114043. %K A114531 nonn %O A114531 0,2 %A A114531 _David Applegate_, Feb 24 2006 %E A114531 More terms from _Peter J. Taylor_, Feb 28 2019