A361016 a(n) = 1 if A004718(n) = 0, otherwise 0, where A004718 is the Danish composer Per Nørgård's "infinity sequence".

1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0

Offset

0

Comments

The composer Per Nørgård's name is also written in the OEIS as Per Noergaard.

Links

Antti Karttunen, Table of n, a(n) for n = 0..65537

Index entries for sequences related to binary expansion of n

Index entries for characteristic functions

Formula

a(n) = [A004718(n) = 0] = [A343029(n) = A343030(n)], where [ ] is the Iverson bracket.

Prog

(PARI)
up_to = 65537;
A004718list(up_to) = { my(v=vector(up_to)); v[1]=1; v[2]=-1; for(n=3, up_to, v[n] = if(n%2, 1+v[n>>1], -v[n/2])); (v); }; \\ After Charles R Greathouse IV's Nov 18 2011 code in A004718.
v004718 = A004718list(up_to);
A004718(n) = if(!n, n, v004718[n]);
A361016(n) = !A004718(n);
(Python)
from itertools import groupby
def A361016(n):
    c = 0
    for k, g in groupby(bin(n)[2:]):
        c = c+len(list(g)) if k == '1' else (-c if len(list(g))&1 else c)
    return int(not c) # Chai Wah Wu, Mar 02 2023

Crossrefs

Characteristic function of A083866.

Cf. A004718, A343029, A343030.

Sequence in context: A133943 A014084 A014159 * A014184 A014359 A079998

Adjacent sequences: A361013 A361014 A361015 * A361017 A361018 A361019

Keyword

nonn

Author

Antti Karttunen, Mar 02 2023

Status

approved