A083866 Positions of zeros in Per Nørgård's infinity sequence (A004718).

0, 5, 10, 17, 20, 27, 34, 40, 45, 54, 65, 68, 75, 80, 85, 90, 99, 105, 108, 119, 130, 136, 141, 150, 160, 165, 170, 177, 180, 187, 198, 210, 216, 221, 238, 257, 260, 267, 272, 277, 282, 291, 297, 300, 311, 320, 325, 330, 337, 340, 347, 354, 360

Offset

0,2

Comments

First differences seem to be always >2.

Many (but not all) prime members are in A005107.

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

Links

Reinhard Zumkeller, Table of n, a(n) for n = 0..10000

Yu Hin (Gary) Au, Christopher Drexler-Lemire, and Jeffrey Shallit, Notes and note pairs in Norgard's infinity series, Journal of Mathematics and Music, Volume 11, Issue 1, 2017, pages 1-19.

Prog

(Haskell)
a083866 n = a083866_list !! n
a083866_list = filter ((== 0) . a004718) [0..]
-- Reinhard Zumkeller, Mar 19 2015, Nov 10 2012
(Python)
from itertools import groupby, islice
def A083866_gen(startvalue=0): # generator of terms >= startvalue
    n, c = max(0, startvalue), 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)
    while True:
        if c == 0: yield n
        n += 1
        c = c-t-1 if (t:=(~n & n-1).bit_length())&1 else t+1-c
A083866_list = list(islice(A083866_gen(), 20)) # Chai Wah Wu, Mar 02 2023

Crossrefs

Cf. A004718, A005107.

Sequence in context: A313946 A313947 A313948 * A313949 A313950 A313951

Adjacent sequences: A083863 A083864 A083865 * A083867 A083868 A083869

Keyword

nonn

Author

Ralf Stephan, May 07 2003

Status

approved