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 A353090 #11 May 07 2022 10:28:54 %S A353090 0,0,1,1,1,2,2,2,3,3,3,4,4,5,5,5,6,6,6,7,7,7,8,8,8,9,9,9,10,10,10,11, %T A353090 11,12,12,12,13,13,13,14,14,14,15,15,15,16,16,16,17,17,18,18,18,19,19, %U A353090 19,20,20,20,21,21,21,22,22,22,23,23,23,24,24,25,25,25,26,26,26,27 %N A353090 Column -2 of the extended Trithoff (tribonacci) array. %C A353090 This column is also called the pre-seed of the Trithoff array. %C A353090 This is a nondecreasing sequence containing all nonnegative integers, with some of them doubled and some tripled. The doubled numbers are the positions of the letter "c" in the tribonacci word (A003146). Correspondingly, the tripled numbers are positions of letters "a" and "b" in the tribonacci word. %C A353090 Suppose number n_1 has tribonacci representation t that ends in 1 (such numbers are in column 1 of the Trithoff array). Then its tribonacci successor n_2 has tribonacci representation t0 (such numbers are in column 2 of the Trithoff array), and the successor of the successor n_3 has tribonacci representation t00 (such numbers are in column 3 of the Trithoff array). The pre-seed in the same row as n_1, n_2, and n_3 is 2n_1-n_2. %Y A353090 Cf. A000073, A003144, A003145, A003146, A136175, A353083, A353084, A353086. %K A353090 nonn %O A353090 1,6 %A A353090 _Tanya Khovanova_ and PRIMES STEP Senior group, Apr 22 2022