A232739 Iterates of Hofstadter's A030124: start with a(1) = A030124(1) = 2, thereafter a(n) = A030124(a(n-1)).

2, 4, 6, 9, 13, 17, 22, 28, 34, 41, 49, 58, 67, 77, 88, 100, 112, 125, 139, 154, 169, 185, 202, 220, 239, 258, 278, 299, 321, 344, 367, 391, 416, 442, 469, 497, 525, 554, 584, 615, 647, 680, 713, 747, 782, 818, 855, 893, 931, 970, 1010, 1051, 1093, 1136, 1179

Offset: 1

Author

Antti Karttunen, Dec 04 2013

Keywords

• nonn

Comments

Is the ratio A005228(n)/a(n) converging towards 1 or some larger value? (Cf. the graph drawn by the OEIS Server's plot2-link).

Cf. also M. F. Hasler's comment in A030124.

Links

• Antti Karttunen, Table of n, a(n) for n = 1..2117
• OEIS Server, Ratio A005228(n)/A232739(n) plotted with Plot 2
• Index entries for Hofstadter-type sequences

Crossrefs

Cf. A005228, A030124, A232751, A232752, A000225, A225850.

Concerning the ratio A005228/A232739 see also A232740, A232750, A232753.

Formula

a(1) = 2, and for n> 1, a(n) = A030124(a(n-1)).

For all n >= 1, A232751(a(n)) = A000225(n+1) and a(n) = A232752(A000225(n+1)) [This is just a consequence of how the permutation pair A232751/A232752 has been defined].

For all n >= 1, a(n) = A225850(a(n+1))/2.