A361313 a(n) = a(1)*a(n-1) + a(2)*a(n-2) + ... + a(n-5)*a(5) for n >= 6, with a(1)=0 and a(2)=a(3)=a(4)=a(5)=1.

0, 1, 1, 1, 1, 0, 1, 1, 2, 3, 4, 8, 11, 20, 31, 52, 88, 143, 247, 408, 700, 1184, 2017, 3462, 5909, 10196, 17518, 30281, 52365, 90704, 157556, 273742, 476893, 831298, 1451603, 2537736, 4441262, 7782934, 13650555, 23969794, 42126241, 74105773, 130476070

Offset: 1

Author

J. Conrad, Mar 08 2023

Keywords

• nonn
• eigen

Comments

Shifts left 5 places under the INVERT transform.

Examples

			a(11) = a(1)*a(10) + a(2)*a(9) + a(3)*a(8) + a(4)*a(7) + a(5)*a(6) = 0*3 + 1*2 + 1*1 + 1*1 + 1*0 = 4.
		

Links

• J. Conrad, Table of n, a(n) for n = 1..3000

Crossrefs

Cf. A025250.

Programs

Python

def A361313(l):
    s = [0, 1, 1, 1, 1][:l]
    for n in range(5, l):
        s.append(sum([s[k] * s[n-k-1] for k in range(n-4)]))
    return s