A287643 a(1) = ... = a(6) = 1; a(n) = a(a(n-3)) + a(n-a(n-6)) for n > 6.

1, 1, 1, 1, 1, 1, 2, 3, 4, 5, 6, 7, 7, 7, 8, 8, 8, 9, 10, 10, 11, 12, 13, 14, 15, 15, 15, 16, 16, 16, 16, 16, 17, 17, 18, 18, 19, 21, 21, 23, 24, 25, 27, 27, 29, 28, 28, 29, 28, 29, 28, 30, 31, 31, 31, 31, 32, 32, 32, 32, 32, 32, 32, 32, 33, 33, 34, 35, 36, 38, 39, 39, 42, 42, 42, 46, 46

Offset: 1

Author

Altug Alkan, May 29 2017

Keywords

• nonn

Comments

This sequence has similar generational structure with A284511. Up to 2^20 see the plot of a(n) - A284511(n) in links section.

Links

• Altug Alkan, Table of n, a(n) for n = 1..10000
• Altug Alkan, Scatterplot of a(n) - A284511(n)

Crossrefs

Cf. A004001, A005185, A284511.

Programs

PARI

q=vector(2^10);q[1]=q[2]=q[3]=q[4]=q[5]=q[6]=1; for(n=7, #q, q[n]=q[q[n-3]]+q[n-q[n-6]]); vector(2^10, n, q[n])