A285582 a(1) = 1, a(2) = a(3) = a(4) = 2; a(n) = a(a(n-3)-1) + a(n-a(n-4)-1) for n > 4.

1, 2, 2, 2, 3, 3, 3, 5, 5, 5, 5, 5, 5, 7, 7, 7, 8, 8, 8, 8, 8, 8, 10, 10, 10, 13, 12, 13, 13, 12, 13, 13, 13, 13, 13, 13, 15, 15, 15, 20, 17, 20, 20, 17, 20, 18, 20, 20, 21, 21, 20, 21, 21, 21, 21, 21, 21, 21, 23, 23, 23, 28, 23, 28, 29, 23, 32, 28, 23, 31, 27, 28, 33, 33, 32

Offset

1,2

Links

Altug Alkan, Table of n, a(n) for n = 1..10000

Altug Alkan, Alternative scatterplot

Mathematica

a[1] = 1; a[2] = a[3] = a[4] = 2; a[n_] := a[n] = a[a[n - 3] - 1] + a[n - a[n - 4] - 1]; Array[a, 75] (* Michael De Vlieger, Apr 23 2017 *)

Prog

(PARI) q=vector(10000); q[1]=1; q[2]=q[3]=q[4]=2; for(n=5, #q, q[n]=q[q[n-3]-1]+q[n-q[n-4]-1]); vector(10000, n, q[n])

Crossrefs

Cf. A005185, A055748, A284523

Sequence in context: A184258 A219291 A029160 * A032562 A076973 A337931

Adjacent sequences: A285579 A285580 A285581 * A285583 A285584 A285585

Keyword

nonn,look

Author

Altug Alkan, Apr 22 2017

Status

approved