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 A296526 #22 Dec 21 2017 07:21:56 %S A296526 1,1,1,2,1,1,1,3,6,3,1,1,1,1,35,60,21,5,1,1,1,2,16,2391,7849,1547,94, %T A296526 9,1,1,1,1,58,1,2757433,21609301,3459386,88193,540,13,1,1,1,4,1,154 %N A296526 Number of connected k-regular graphs on 2*n nodes with maximal diameter D(n,k) A296525 written as array T(n,k), 2 <= k < 2*n. %D A296526 See A296525 for references and links. %e A296526 Degree r %e A296526 2 3 4 5 6 7 8 9 10 11 12 13 14 15 %e A296526 n ------------------------------------------------------------------ %e A296526 4 | 2 1 Diameter A296525 %e A296526 | 1 1 Number of graphs with this diameter (this sequence) %e A296526 | %e A296526 6 | 3 2 2 1 %e A296526 | 1 2 1 1 %e A296526 | %e A296526 8 | 4 3 2 2 2 1 %e A296526 | 1 3 6 3 1 1 %e A296526 | %e A296526 10 | 5 5 3 2 2 2 2 1 %e A296526 | 1 1 35 60 21 5 1 1 %e A296526 | %e A296526 12 | 6 6 4 3 2 2 2 2 2 1 %e A296526 | 1 2 16 2391 7849 1547 94 9 1 1 %e A296526 | %e A296526 14 | 7 8 5 5 3 2 2 2 2 2 2 1 %e A296526 | 1 1 58 1 2757433 21609301 3459386 88193 540 13 1 1 %e A296526 | lower bounds %e A296526 16 | 8 9 7 5 >=4 >=3 2 2 2 2 2 2 2 1 %e A296526 | 1 4 1 154 ? ? ? ? ? ?4207 21 1 1 %e A296526 | lower bounds %e A296526 18 | 9 11 >=8 >=6 >=4 >=4 >=3 2 2 2 2 2 2 2 %e A296526 | 1 1 ? ? ? ? ? ? ? ? ? ?42110 33 %e A296526 . %e A296526 a(35)=1 corresponds to the only 5-regular graph on 14 nodes with diameter 5. %e A296526 Its adjacency matrix is %e A296526 . %e A296526 1 2 3 4 5 6 7 8 9 0 1 2 3 4 %e A296526 1 . 1 1 1 1 1 . . . . . . . . %e A296526 2 1 . 1 1 1 1 . . . . . . . . %e A296526 3 1 1 . 1 1 . 1 . . . . . . . %e A296526 4 1 1 1 . . 1 1 . . . . . . . %e A296526 5 1 1 1 . . 1 1 . . . . . . . %e A296526 6 1 1 . 1 1 . 1 . . . . . . . %e A296526 7 . . 1 1 1 1 . 1 . . . . . . %e A296526 8 . . . . . . 1 . 1 1 1 1 . . %e A296526 9 . . . . . . . 1 . 1 1 . 1 1 %e A296526 10 . . . . . . . 1 1 . . 1 1 1 %e A296526 11 . . . . . . . 1 1 . . 1 1 1 %e A296526 12 . . . . . . . 1 . 1 1 . 1 1 %e A296526 13 . . . . . . . . 1 1 1 1 . 1 %e A296526 14 . . . . . . . . 1 1 1 1 1 . %e A296526 . %e A296526 A shortest walk along 5 edges is required to reach node 13 from node 1. %e A296526 All others of the A068934(97)=3459383 5-regular graphs on 14 nodes have smaller diameters, i.e., 258474 with diameter 2, 3200871 with diameter 3, and 37 with diameter 4 (see A296621). %Y A296526 Cf. A068934, A204329, A294733, A296524, A296525, A296621. %K A296526 nonn,tabf,hard,more %O A296526 2,4 %A A296526 _Hugo Pfoertner_, Dec 14 2017