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 A026354 #12 Dec 21 2023 21:14:16 %S A026354 1,2,3,3,4,5,4,6,5,7,8,6,9,10,7,11,8,12,13,9,14,10,15,16,11,17,18,12, %T A026354 19,13,20,21,14,22,23,15,24,16,25,26,17,27,18,28,29,19,30,31,20,32,21, %U A026354 33,34,22,35,23,36,37,24,38,39,25,40,26,41,42 %N A026354 a(n) = a(m) if a(m) has already occurred exactly once and n = a(m)+m-2, else a(n) = least positive integer that has not yet occurred. %H A026354 Jeffrey Shallit, <a href="/A026354/a026354.pdf">Automaton for a(n)</a> %F A026354 a(n)=n for n<4, a(n)=A026242(n-2)+2 for all n>2, a(n)=A026272(n-4)+3 for n>4. - _M. F. Hasler_, Sep 17 2014 %F A026354 There is a 35-state automaton that accepts, in parallel, the Fibonacci (Zeckendorf) representation of n and a(n). See the file a026354.pdf. - _Jeffrey Shallit_, Dec 21 2023 %o A026354 (PARI) A026354=vector(2+#A026242,n,if(n>3,A026242[n-2]+2,n)) \\ Assumes the vector A026242 is defined, see there for PARI code. - _M. F. Hasler_, Sep 17 2014 %Y A026354 Cf. A026272. %K A026354 nonn %O A026354 1,2 %A A026354 _Clark Kimberling_