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 A343998 #9 Jun 11 2021 12:47:47 %S A343998 1,2,1,4,2,2,3,8,4,2,5,4,6,4,3,16,8,4,9,8,3,6,11,8,12,6,13,4,14,8,15, %T A343998 32,6,8,7,4,18,10,6,8,20,10,21,16,5,12,23,16,24,12,9,20,26,14,5,24,9, %U A343998 14,29,8,30,16,14,64,13,6,33,8,12,10,35,32,36,18,12,28,11,6,39,32,40,20,41,24,17,22 %N A343998 a(n) = A343997(n)/2. %o A343998 (Python) %o A343998 from sympy.ntheory.modular import crt %o A343998 from sympy import factorint %o A343998 from itertools import product %o A343998 def A343998(n): %o A343998 fs = factorint(2*n) %o A343998 plist = [p**fs[p] for p in fs] %o A343998 return (1+min(k for k in (crt(plist,d)[0] for d in product([0,-1],repeat=len(plist))) if k > 0))//2 # _Chai Wah Wu_, Jun 01 2021 %Y A343998 Cf. A343997. %K A343998 nonn %O A343998 1,2 %A A343998 _N. J. A. Sloane_, Jun 01 2021