A006158 - OEIS

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A006158

a(n) = a(a(n-3)) + a(n-a(n-3)).
(Formerly M0447)

1, 1, 1, 2, 3, 4, 4, 4, 5, 6, 6, 7, 8, 8, 8, 8, 9, 10, 10, 11, 12, 13, 13, 14, 15, 16, 16, 16, 16, 16, 16, 16, 17, 18, 18, 19, 20, 21, 21, 22, 23, 24, 25, 25, 26, 27, 28, 29, 29, 29, 29, 29, 30, 31, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 33, 34, 34, 35, 36, 37, 37, 38, 39, 40, 41

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,4

REFERENCES

J. Arkin, D. C. Arney, L. S. Dewald and W. E. Ebel, Jr., Families of recursive sequences, J. Rec. Math., 22 (No. 22, 1990), 85-94.

B. W. Conolly, ``Meta-Fibonacci sequences,'' in S. Vajda, editor, Fibonacci and Lucas Numbers and the Golden Section. Halstead Press, NY, 1989, pp. 127-138.

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

LINKS

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

I. Vardi, Email to N. J. A. Sloane, Jun. 1991

MAPLE

a := proc(n) option remember: if 1 <= n and n <=3 then RETURN(1) fi: a(a(n-3)) +a(n-a(n-3)) end: for n from 1 to 100 do printf(`%d, `, a(n)) od:

PROG

(PARI) first(n) = my(res = vector(n, i, 1)); for(x=4, n, res[x]=res[res[x-3]] + res[x-res[x-3]]); res \\ Iain Fox, Oct 24 2018

CROSSREFS

Sequence in context: A173073 A073425 A087876 * A340203 A135414 A326821

Adjacent sequences: A006155 A006156 A006157 * A006159 A006160 A006161

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from James A. Sellers, Apr 20 2001

STATUS

approved