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 A301851 #22 Oct 29 2021 06:05:18 %S A301851 1,2,2,3,3,3,4,5,5,4,5,7,6,7,5,6,9,9,9,9,6,7,11,12,10,12,11,7,8,13,15, %T A301851 14,14,15,13,8,9,15,18,17,15,17,18,15,9,10,17,21,21,19,19,21,21,17,10, %U A301851 11,19,24,25,24,20,24,25,24,19,11,12,21,27,29,29,26,26,29,29,27,21,12 %N A301851 Table read by antidiagonals: T(n, k) gives the number of distinct distances on an n X k pegboard. %C A301851 Main diagonal is A047800. %H A301851 Peter Kagey, <a href="/A301851/b301851.txt">Table of n, a(n) for n = 1..10000</a> %e A301851 The 4 X 6 pegboard has 17 distinct distances: 0, 1, sqrt(2), 2, sqrt(5), sqrt(8), 3, sqrt(10), sqrt(13), 4, sqrt(17), sqrt(18), sqrt(20), 5, sqrt(26), sqrt(29), and sqrt(34). %e A301851 +---+---+---+---+---+---+ %e A301851 | * | | | | 16| 25| %e A301851 +---+---+---+---+---+---+ %e A301851 | 1 | 2 | | | 17| 26| %e A301851 +---+---+---+---+---+---+ %e A301851 | 4 | 5 | 8 | | 20| 29| %e A301851 +---+---+---+---+---+---+ %e A301851 | 9 | 10| 13| 18| | 34| %e A301851 +---+---+---+---+---+---+ %e A301851 (As depicted, the pegs are at the center of each face.) %e A301851 Square array begins: %e A301851 n\k| 1 2 3 4 5 6 7 8 %e A301851 ---+---------------------------------------- %e A301851 1| 1 2 3 4 5 6 7 8 %e A301851 2| 2 3 5 7 9 11 13 15 %e A301851 3| 3 5 6 9 12 15 18 21 %e A301851 4| 4 7 9 10 14 17 21 25 %e A301851 5| 5 9 12 14 15 19 24 29 %e A301851 6| 6 11 15 17 19 20 26 31 %e A301851 7| 7 13 18 21 24 26 27 33 %e A301851 8| 8 15 21 25 29 31 33 34 %o A301851 (Haskell) %o A301851 import Data.List (nub) %o A301851 a301851 n k = length $ nub [i^2 + j^2 | i <- [0..n-1], j <- [0..k-1]] %Y A301851 Cf. A001481, A047800, A225273, A301853. %K A301851 nonn,tabl %O A301851 1,2 %A A301851 _Peter Kagey_, Mar 27 2018