A286387 a(n) = A002487(n^2).

0, 1, 1, 4, 1, 7, 4, 9, 1, 14, 7, 13, 4, 29, 9, 16, 1, 23, 14, 43, 7, 36, 13, 29, 4, 43, 29, 64, 9, 67, 16, 25, 1, 34, 23, 89, 14, 115, 43, 46, 7, 85, 36, 79, 13, 46, 29, 79, 4, 97, 43, 142, 29, 89, 64, 91, 9, 136, 67, 157, 16, 121, 25, 36, 1, 47, 34, 151, 23, 236, 89, 157, 14, 211, 115, 104, 43, 225, 46, 109, 7, 162, 85, 235, 36, 139, 79, 174, 13, 101, 46

Offset: 0

Author

Antti Karttunen, May 09 2017

Keywords

• nonn

Comments

Conjecture: For all i >= 0, j >= 0: A103391(1+i) = A103391(1+j) => a(i) = a(j). This would be an implication of observation made at A286377, which has been checked up to n=2048. See also A286378.

Links

• Antti Karttunen, Table of n, a(n) for n = 0..8192
• Index entries for sequences related to Stern's sequences

Crossrefs

Cf. A000290, A002487, A103391, A286377, A286378.

Programs

Python

from functools import reduce
def A286387(n): return sum(reduce(lambda x,y:(x[0],x[0]+x[1]) if int(y) else (x[0]+x[1],x[1]),bin(n**2)[-1:2:-1],(1,0))) if n else 0 # Chai Wah Wu, May 18 2023

Scheme

(define (A286387 n) (A002487 (* n n)))

Formula

a(n) = A002487(A000290(n)) = A002487(n^2).