A283883 - OEIS

A283883

Relative of Hofstadter Q-sequence: a(n) = max(0, n+117) for n <= 0; a(n) = a(n-a(n-1)) + a(n-a(n-2)) for n > 0.

3, 118, 119, 5, 120, 6, 7, 121, 123, 10, 8, 123, 127, 12, 124, 14, 129, 11, 128, 132, 16, 13, 17, 15, 131, 20, 20, 242, 123, 24, 32, 238, 3, 32, 357, 5, 238, 3, 5, 595, 5, 238, 3, 5, 833, 5, 238, 3, 5, 1071, 5, 238, 3, 5, 1309, 5, 238, 3, 5, 1547, 5, 238, 3, 5, 1785, 5, 238, 3, 5, 2023, 5, 238, 3, 5, 2261

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OFFSET

1,1

COMMENTS

Sequences like this are more naturally considered with the first nonzero term in position 1. But this sequence would then match A000027 for its first 117 terms.

This sequence has exactly 3346939303954 terms (of positive index). a(3346939303954) = 0, so an attempt to calculate a(3346939303955) would refer to itself.

LINKS

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

FORMULA

If the index is between 35 and 122 (inclusive), then a(5n) = 238n-1309, a(5n+1) = 5, a(5n+2) = 238, a(5n+3) = 3, a(5n+4) = 5.

If the index is between 128 and 4525 (inclusive), then a(5n) = 4641, a(5n+1) = 3, a(5n+2) = 5, a(5n+3) = 4641n-106981, a(5n+4) = 5.

If the index is between 4531 and 4093008 (inclusive), then a(5n) = 5, a(5n+1) = 4093124n-3700188737, a(5n+2) = 5, a(5n+3) = 4093124, a(5n+4) = 3.

If the index is between 4093008 and 3346939303796 (inclusive), then a(5n) = 5, a(5n+1) = 3346939303911, a(5n+2) = 3, a(5n+3) = 5, a(5n+4) = 3346939303911n-2739804514185637724.

MAPLE

A283883:=proc(n) option remember: if n <= 0 then max(0, n+117): else A283883(n-A283883(n-1)) + A283883(n-A283883(n-2)): fi: end:

CROSSREFS

Cf. A005185, A274058, A283883.

Sequence in context: A326995 A155209 A037117 * A173053 A180393 A172013

Adjacent sequences: A283880 A283881 A283882 * A283884 A283885 A283886

KEYWORD

nonn,fini

AUTHOR

Nathan Fox, Mar 19 2017

STATUS

approved