|
%I #16 Oct 05 2018 09:57:35
%S 1,5,9,13,16,20,24,28,31,35,39,43,46,50,54,57,61,65,69,72,76,80,84,87,
%T 91,95,99,102,106,110,113,117,121,125,128,132,136,140,143,147,151,155,
%U 158,162,166,169,173,177,181,184,188,192,196,199,203,207
%N a(1)=1; for n>1, a(n)=a(n-1)+3 if n is already in the sequence, a(n)=a(n-1)+4 otherwise.
%H Reinhard Zumkeller, <a href="/A080590/b080590.txt">Table of n, a(n) for n = 1..10000</a>
%H B. Cloitre, N. J. A. Sloane and M. J. Vandermast, <a href="http://www.cs.uwaterloo.ca/journals/JIS/VOL6/Cloitre/cloitre2.html">Numerical analogues of Aronson's sequence</a>, J. Integer Seqs., Vol. 6 (2003), #03.2.2.
%H B. Cloitre, N. J. A. Sloane and M. J. Vandermast, <a href="http://arXiv.org/abs/math.NT/0305308">Numerical analogues of Aronson's sequence</a> (math.NT/0305308)
%t a[n_] := a[n] = If[n == 1, 1, If[MemberQ[Array[a, n-1], n], a[n-1]+3, a[n-1]+4]]; Array[a, 56] (* _Jean-François Alcover_, Oct 05 2018 *)
%o (Haskell)
%o a080590 n = a080590_list !! (n-1)
%o a080590_list = 1 : f 2 [1] where
%o f x zs@(z:_) = y : f (x + 1) (y : zs) where
%o y = z + (if x `elem` zs then 3 else 4)
%o -- _Reinhard Zumkeller_, Sep 26 2014
%Y Cf. A003151, A080455-A080458, A080036, A080037.
%Y Cf. A081834.
%K nonn
%O 1,2
%A _N. J. A. Sloane_, Mar 23 2003
|
