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A278056 Relative of Hofstadter Q-sequence: a(n) = n for 1 <= n <= 4; a(n) = a(n-a(n-1)) + a(n-a(n-2)) for n > 4. 11
1, 2, 3, 4, 3, 5, 6, 5, 7, 6, 7, 8, 8, 10, 9, 11, 10, 11, 12, 12, 14, 11, 15, 15, 12, 17, 15, 15, 20, 15, 18, 20, 17, 20, 20, 22, 19, 23, 23, 20, 25, 21, 22, 26, 27, 24, 27, 29, 23, 29, 26, 32, 29, 23, 37, 29, 27, 38, 34, 28, 32, 35, 33, 38, 35, 33, 40, 35, 40 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Similar to Hofstadter's Q-sequence A005185 but with different starting values.

Much like the Hofstadter Q-sequence, it is not known if this sequence is defined for all positive n.

a(n) exists for n <= 3*10^7.

LINKS

Nathan Fox, Table of n, a(n) for n = 1..10000

Altug Alkan, On a Generalization of Hofstadter's Q-Sequence: A Family of Chaotic Generational Structures, Complexity (2018) Article ID 8517125.

N. Fox, Hofstadter-like Sequences over Nonstandard Integers, Talk given at the Rutgers Experimental Mathematics Seminar, November 10 2016.

MATHEMATICA

Nest[Append[#1, #1[[#2 - #1[[-1]] ]] + #1[[#2 - #1[[-2]] ]]] & @@ {#, 1 + Length@ #} &, Range@ 4, 65] (* Michael De Vlieger, Sep 26 2018 *)

CROSSREFS

Cf. A005185, A278057, A278058, A278059, A278060, A278061, A278062, A278063, A278064, A278065.

Sequence in context: A325277 A257573 A182973 * A324345 A324533 A141128

Adjacent sequences:  A278053 A278054 A278055 * A278057 A278058 A278059

KEYWORD

nonn

AUTHOR

Nathan Fox, Nov 10 2016

STATUS

approved

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Last modified May 14 12:07 EDT 2021. Contains 343882 sequences. (Running on oeis4.)