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A292603
Doudna-tree reduced modulo 4: a(n) = A005940(1+n) mod 4.
3
1, 2, 3, 0, 1, 2, 1, 0, 3, 2, 3, 0, 1, 2, 3, 0, 3, 2, 1, 0, 3, 2, 1, 0, 1, 2, 3, 0, 1, 2, 1, 0, 1, 2, 1, 0, 3, 2, 3, 0, 1, 2, 1, 0, 3, 2, 3, 0, 1, 2, 3, 0, 1, 2, 1, 0, 3, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3, 0, 1, 2, 3, 0, 3, 2, 1, 0, 3, 2, 1, 0, 3, 2, 3, 0, 1, 2, 3, 0, 3, 2, 1, 0, 3, 2, 1, 0, 1, 2, 3, 0, 1, 2, 1, 0, 3, 2, 3, 0, 1, 2, 3, 0, 3, 2, 1, 0, 3, 2, 1, 0, 1
OFFSET
0,2
FORMULA
a(n) = A010873(A005940(1+n)).
a(n) + 4*A292602(n) = A005940(1+n).
a(2n+1) = 2*a(n) mod 4.
a(A004767(n)) = 0.
a(A016813(n)) = 2.
a(2*A156552(A246261(n))) = 1.
a(2*A156552(A246263(n))) = 3.
a(n * 2^(1+A246271(A005940(1+n)))) = 1.
EXAMPLE
The first six levels of the binary tree (compare also to the illustrations given at A005940 and A292602):
1
|
2
............../ \..............
3 0
....../ \...... ....../ \......
1 2 1 0
/ \ / \ / \ / \
/ \ / \ / \ / \
3 2 3 0 1 2 3 0
/ \ / \ / \ / \ / \ / \ / \ / \
3 2 1 0 3 2 1 0 1 2 3 0 1 2 1 0
PROG
(Scheme) (define (A292603 n) (modulo (A005940 (+ 1 n)) 4))
CROSSREFS
Cf. A004767 (gives the positions of 0's), A016813 (of 2's).
Sequence in context: A308322 A308898 A106728 * A308880 A319047 A276335
KEYWORD
nonn
AUTHOR
Antti Karttunen, Dec 01 2017
STATUS
approved