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 A070879 #23 Jan 05 2025 19:51:37 %S A070879 1,1,1,1,2,1,1,1,3,2,3,1,2,1,1,1,4,3,5,2,5,3,4,1,3,2,3,1,2,1,1,1,5,4, %T A070879 7,3,8,5,7,2,7,5,8,3,7,4,5,1,4,3,5,2,5,3,4,1,3,2,3,1,2,1,1,1,6,5,9,4, %U A070879 11,7,10,3,11,8,13,5,12,7,9,2,9,7,12,5,13,8,11,3,10,7,11,4,9,5,6,1,5,4,7,3,8 %N A070879 Stern's diatomic array read by rows (version 3 - same as version 2, A070878, but with final 0 in each row omitted). %C A070879 Row n has length 2^n. %C A070879 From _Yosu Yurramendi_, Apr 08 2019: (Start) %C A070879 The terms (n>0) may be written as a left-justified array with rows of length 2^m: %C A070879 1, %C A070879 1, 1, %C A070879 1, 2, 1, 1, %C A070879 1, 3, 2, 3, 1, 2, 1, 1, %C A070879 1, 4, 3, 5, 2, 5, 3, 4, 1, 3, 2, 3, 1, 2, 1, 1, %C A070879 1, 5, 4, 7, 3, 8, 5, 7, 2, 7, 5, 8, 3, 7, 4, 5, 1, 4, 3, 5, 2, 5, 3, 4,... %C A070879 as well as right-justified fashion: %C A070879 1, %C A070879 1, 1, %C A070879 1, 2, 1, 1, %C A070879 1, 3, 2, 3, 1, 2, 1, 1, %C A070879 1, 4, 3, 5, 2, 5, 3, 4, 1, 3, 2, 3, 1, 2, 1, 1, %C A070879 ... , 2, 7, 5, 8, 3, 7, 4, 5, 1, 4, 3, 5, 2, 5, 3, 4, 1, 3, 2, 3, 1, 2, 1, 1, %C A070879 ... %C A070879 For properties see FORMULA section. %C A070879 (End) %H A070879 C. Giuli and R. Giuli, <a href="https://web.archive.org/web/2024*/https://www.fq.math.ca/Scanned/17-2/giuli.pdf">A primer on Stern's diatomic sequence</a>, Fib. Quart., 17 (1979), 103-108, 246-248 and 318-320 (but beware errors). %H A070879 <a href="/index/St#Stern">Index entries for sequences related to Stern's sequences</a> %F A070879 From _Yosu Yurramendi_, Apr 08 2019: (Start) %F A070879 a(2^(m+1)+k-1) = A002487(2^m+k); a(2^(m+1)+2^m+k-1) = a(2^m+k-1) for m >= 0, 0 <= k < 2^m. %F A070879 a(2^(m+1)-1-(k+1)) = A002487(k+1); a(2^(m+1)+k) - a(2^m+k) = A002487(k) for m >= 0, 0 <= k < 2^m. %F A070879 a(2^m-1) = 1 for m >= 0; a(2^(m+1)+k-1) = a(2^(m+1)-k-1) + a(2^m+k-1) for m >= 0, 0 < k < 2^m. %F A070879 a(2^m+2^m'+k'-1) = a(2^(m'+1)+k'-1)*(m-m'-1) + a(2^m'+k'-1) for m >= 1, 0 <= m' < m, 0 <= k' < 2^m'. %F A070879 (End) %Y A070879 Cf. A049456, A070878, A049455. %Y A070879 Rows sums are A007051. %K A070879 nonn,tabf,easy %O A070879 0,5 %A A070879 _N. J. A. Sloane_, May 20 2002 %E A070879 More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Apr 07 2003