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 A309376 #10 Aug 01 2019 05:41:36 %S A309376 0,0,1,3,7,1,22,42,6,58,108,19,246,331,399,724,1045,1435,202,1890, %T A309376 2269,342,3675,7164,8365,1177,10815,12910,1944,18756,24139,33784, %U A309376 48756,6138,73671,106597,124848,128557,20188,231441,284172,39963,336567,360472,421512,62896,605881,730627,819127,110143,1100122,1656277,232918,2099832,2306866,2411752,358911,3445662 %N A309376 a(n) appears in the congruences modulo 4 or 32 of Markoff numbers m(n) = A002559(n) for odd or even m(n). %C A309376 See the Aigner reference, Proposition 3.13., p. 55. %C A309376 If m(n) is odd then m(n) = 1 + 4*a(n), and if m(n) is even then m(n) = 2 + 32* a(n). %D A309376 Martin Aigner, Markov's Theorem and 100 Years of the Uniqueness Conjecture, Springer, 2013, p. 55. %F A309376 If m(n) is odd then a(n) = (m(n) - 1)/4, and if m(n) is even then a(n) = (m(n) - 2)/32, for the Markoff numbers m(n) = A002559(n), for n >= 1. %e A309376 a(3) = 1 because m(3) - 1 = 4 = a(3)*4. m(3) is odd. %e A309376 a(6) = 1 because m(6) - 2 = 32 = a(6)*32. m(6) is even. %Y A309376 Cf. A002559. %K A309376 nonn,easy %O A309376 1,4 %A A309376 _Wolfdieter Lang_, Jul 26 2019