A163343 Central diagonal of A163334 and A163336.

0, 4, 8, 44, 40, 36, 72, 76, 80, 404, 400, 396, 360, 364, 368, 332, 328, 324, 648, 652, 656, 692, 688, 684, 720, 724, 728, 3644, 3640, 3636, 3600, 3604, 3608, 3572, 3568, 3564, 3240, 3244, 3248, 3284, 3280, 3276, 3312, 3316, 3320, 2996, 2992, 2988

Offset: 0

Author

Antti Karttunen, Jul 29 2009

Keywords

• nonn

Comments

It is easy to see by induction that these terms are always divisible by 4.

Crossrefs

Cf. A163344 (quarter), A128173, A163332, A163334, A338086.

Peano curve axes: A163480, A163481.

Programs

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

Formula

a(n) = 4*A163344(n).

a(n) = A163332(A338086(n)) = A338086(A128173(n)). - Kevin Ryde, Nov 06 2020