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A051135 a(n) = number of times n appears in the Hofstadter-Conway $10000 sequence A004001. 8
2, 2, 1, 3, 1, 1, 2, 4, 1, 1, 1, 2, 1, 2, 3, 5, 1, 1, 1, 1, 2, 1, 1, 2, 1, 2, 3, 1, 2, 3, 4, 6, 1, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 2, 1, 2, 3, 1, 1, 2, 1, 2, 3, 1, 2, 3, 4, 1, 2, 3, 4, 5, 7, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 2, 1, 2, 3, 1, 1, 1, 2, 1, 1, 2, 1, 2, 3, 1, 1, 2, 1, 2, 3, 1, 2, 3 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

If the initial 2 is changed to a 1, the resulting sequence has the property that if all 1's are deleted, the remaining terms are the sequence incremented. - Franklin T. Adams-Watters, Oct 05 2006

a(A088359(n))=1 and a(A087686(n))>1; first differences of A188163. [Reinhard Zumkeller, Jun 03 2011]

Start:

a(k)=1 for k= 3, 5, 6, 9, 10, 11, 13, 17, 18, 19, 20, 22, 23, 25, 28, ..., ;

a(k)=2 for k= 1, 2, 7, 12, 14, 21, 24, 26, 29, 38, 42, 45, 47, 51, 53, ..., ;

a(k)=3 for k= 4, 15, 27, 30, 48, 54, 57, 61, 86, 96, 102, 105, 112, ..., ;

a(k)=4 for k= 8, 31, 58, 62, 106, 116, 120, 125, 192, 212, 222, 226, ..., ;

a(k)=5 for k= 16, 63, 121, 126, 227, 242, 247, 253, 419, 454, 469, ..., ;

a(k)=6 for k= 32, 127, 248, 254, 475, 496, 502, 509, 894, 950, 971, ..., ;

a(k)=7 for k= 64, 255, 503, 510, 978, 1006, 1013, 1021, 1872, 1956, ..., ;

a(k)=8 for k= 128, 511, 1014, 1022, 1992, 2028, 2036, 2045, 3864, ..., ;

a(k)=9 for k= 256, 1023, 2037, 2046, 4029, 4074, 4083, 4093, 7893, ..., ;

a(k)=10 for k= 512, 2047, 4084, 4094, 8113, 8168, 8178, 8189, ..., ; etc. Robert G. Wilson v, June 7 2011.

LINKS

_Reinhard Zumkeller_, Table of n, a(n) for n = 1..10000

Wikipedia, Hofstadter sequence

Eric Weisstein's World of Mathematics, Hofstadter-Conway $10,000 Sequence.

Index entries for Hofstadter-type sequences

MAPLE

a[1]:=1: a[2]:=1: for n from 3 to 300 do a[n]:=a[a[n-1]]+a[n-a[n-1]] od: A:=[seq(a[n], n=1..300)]:for j from 1 to A[nops(A)-1] do c[j]:=0: for n from 1 to 300 do if A[n]=j then c[j]:=c[j]+1 else fi od: od: seq(c[j], j=1..A[nops(A)-1]); - Emeric Deutsch, Jun 06 2006

MATHEMATICA

a[1] = 1; a[2] = 1; a[n_] := a[n] = a[a[n - 1]] + a[n - a[n - 1]]; t = Array[a, 250]; Take[ Transpose[ Tally[t]][[2]], 105] (* Robert G. Wilson v, June 7 2011 *)

PROG

(Haskell)

import Data.List (group)

a051135 n = a051135_list !! (n-1)

a051135_list = map length $ group a004001_list

-- Reinhard Zumkeller, Jun 03 2011

CROSSREFS

Cf. A004001, A088359.

Sequence in context: A116687 A056044 A116685 * A135352 A072528 A166363

Adjacent sequences:  A051132 A051133 A051134 * A051136 A051137 A051138

KEYWORD

easy,nonn,nice

AUTHOR

Robert Lozyniak (11(AT)onna.com)

EXTENSIONS

More terms from Jud McCranie

STATUS

approved

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Last modified May 23 07:10 EDT 2013. Contains 225585 sequences.