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 A305574 #15 Feb 15 2023 10:03:20 %S A305574 5,2,7,30,143,728,3876,21318,120175,690690,4032015,23841480,142498692, %T A305574 859515920,5225264024,31983672534,196947587823,1219199353190, %U A305574 7583142491925,47365474641870,296983176369495,1868545312633440,11793499763070480,74650344244967400 %N A305574 Number of primitive (1,1) pairs in the Fibonacci tree at depth 3n. %D A305574 John Charles Saunders, Problems in Combinatorial and Analytic Number Theory, Ph. D. thesis, University of Waterloo, 2018. %H A305574 Kevin G. Hare, and J. C. Saunders, <a href="https://arxiv.org/abs/1608.03522">On (a,b) Pairs in Random Fibonacci Sequences</a>, Arxiv preprint arXiv:1608.03522 [math.NT], February 2018. %o A305574 (PARI) {a(n) = my(A); if( n<=1, 5*(n==1), A = O(x); for(k=1, n, A = x / (1 - A)^2); polcoeff(A, n))}; /* _Michael Somos_, Dec 10 2019 */ %Y A305574 Cf. A006013. %K A305574 nonn %O A305574 1,1 %A A305574 _Jeffrey Shallit_, Jun 05 2018 %E A305574 More terms added and a(14) corrected by _Michael Somos_, Dec 10 2019