cp's OEIS Frontend

A003249 a(n) = A001950(A003234(n)) + 1.

%I A003249 M4492 #31 Jan 05 2025 19:51:33
%S A003249 8,21,29,42,50,55,63,76,84,97,110,118,131,139,144,152,165,173,186,194,
%T A003249 199,207,220,228,241,254,262,275,283,288,296,309,317,330,338,343,351,
%U A003249 364,372,377,385,398,406,419,427,432,440,453,461,474,487,495,508,516
%N A003249 a(n) = A001950(A003234(n)) + 1.
%C A003249 This is the function named u' in [Carlitz]. - _Eric M. Schmidt_, Aug 14 2014
%D A003249 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H A003249 L. Carlitz, R. Scoville and T. Vaughan, <a href="https://web.archive.org/web/2024*/https://www.fq.math.ca/Scanned/11-4/carlitz.pdf">Some arithmetic functions related to Fibonacci numbers</a>, Fib. Quart., 11 (1973), 337-386.
%p A003249 A003249 := proc(n)
%p A003249     A001950(A003234(n)) +1 ;
%p A003249 end proc:
%p A003249 seq(A003249(n),n=1..80) ; # _R. J. Mathar_, Jul 16 2024
%t A003249 nmax = 80;
%t A003249 A001950[n_] := Floor[n*GoldenRatio^2];
%t A003249 A003231[n_] := 2*n + Floor[n*GoldenRatio];
%t A003249 A003234 = Select[Range[4*nmax],
%t A003249    A003231[A001950[#]] == A001950[A003231[#]] - 1&];
%t A003249 a[n_] := A001950[A003234[[n]]] + 1;
%t A003249 Table[a[n], {n, 1, nmax}] (* _Jean-François Alcover_, Jul 21 2024 *)
%o A003249 (Haskell)
%o A003249 a003249 = (+ 1) . a001950 . a003234 -- _Reinhard Zumkeller_, Oct 03 2014
%Y A003249 Cf. A242094 (complement), A001950, A003234.
%K A003249 nonn
%O A003249 1,1
%A A003249 _N. J. A. Sloane_
%E A003249 Corrected and extended by, and a definition from _Eric M. Schmidt_, Aug 14 2014