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 A163343 #6 Nov 06 2020 23:49:06 %S A163343 0,4,8,44,40,36,72,76,80,404,400,396,360,364,368,332,328,324,648,652, %T A163343 656,692,688,684,720,724,728,3644,3640,3636,3600,3604,3608,3572,3568, %U A163343 3564,3240,3244,3248,3284,3280,3276,3312,3316,3320,2996,2992,2988 %N A163343 Central diagonal of A163334 and A163336. %C A163343 It is easy to see by induction that these terms are always divisible by 4. %F A163343 a(n) = 4*A163344(n). %F A163343 a(n) = A163332(A338086(n)) = A338086(A128173(n)). - _Kevin Ryde_, Nov 06 2020 %o A163343 (PARI) a(n) = my(v=digits(n,3),s=Mod(0,2)); for(i=1,#v, if(s,v[i]=2-v[i]); s+=v[i]); fromdigits(v,9)<<2; \\ _Kevin Ryde_, Nov 06 2020 %Y A163343 Cf. A163344 (quarter), A128173, A163332, A163334, A338086. %Y A163343 Peano curve axes: A163480, A163481. %K A163343 nonn %O A163343 0,2 %A A163343 _Antti Karttunen_, Jul 29 2009