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 A362937 #13 Aug 29 2023 10:12:16 %S A362937 0,0,1,2,4,4,7,10,14,18,23,26,32,38,43,50,58,64,73,80,90,100,111,120, %T A362937 132,144,157,168,182,192,207,222,238,254,269,284,302,320,339,356,376, %U A362937 392,413,434,452,474,497,518,542,566,591,616,642,666,693,718,746,774,803,826,856,886,915,946,978 %N A362937 a(n) = (A000982(n) - A362931(n))/2. %C A362937 a(n) = one-half of (number of pairs (i,j) in [1..n] X [1..n] with integral arithmetic mean) - (number of pairs (i,j) in [1..n] X [1..n] with integral harmonic mean). %H A362937 Alois P. Heinz, <a href="/A362937/b362937.txt">Table of n, a(n) for n = 1..10000</a> %o A362937 (Python) %o A362937 def A362937(n): return ((n-1)**2>>2)-sum(1 for x in range(1,n+1) for y in range(1,x) if not (x*y<<1)%(x+y)) # _Chai Wah Wu_, Aug 29 2023 %Y A362937 Cf. A000982, A362931-A362936. %K A362937 nonn %O A362937 1,4 %A A362937 _N. J. A. Sloane_, Aug 28 2023