The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A002053

(Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A002053

a(n) = least value of m for which Liouville's function A002819(m) = -n.
(history; published version)

#33 by OEIS Server at Mon Jan 02 02:17:12 EST 2023

LINKS

Chai Wah Wu, <a href="/A002053/b002053_1.txt">Table of n, a(n) for n = 0..10000</a> (n = 0..2000 from T. D. Noe)

#32 by Joerg Arndt at Mon Jan 02 02:17:12 EST 2023

STATUS

reviewed

approved

Discussion

Mon Jan 02

02:17

OEIS Server: Installed new b-file as b002053.txt.  Old b-file is now b002053_1.txt.

#31 by Michel Marcus at Mon Jan 02 01:26:34 EST 2023

STATUS

proposed

reviewed

#30 by Chai Wah Wu at Sun Jan 01 23:04:02 EST 2023

STATUS

editing

proposed

#29 by Chai Wah Wu at Sun Jan 01 23:03:41 EST 2023

LINKS

T. D. Noe, Chai Wah Wu, <a href="/A002053/b002053_1.txt">Table of n, a(n) for n = 0..10000</a> (n = 0..2000</a> from T. D. Noe)

STATUS

approved

editing

#28 by Alois P. Heinz at Sun Jan 01 19:26:12 EST 2023

STATUS

proposed

approved

#27 by Chai Wah Wu at Sun Jan 01 19:18:05 EST 2023

STATUS

editing

proposed

#26 by Chai Wah Wu at Sun Jan 01 19:17:57 EST 2023

PROG

(Python)

from functools import reduce

from operator import ixor

from itertools import count

from sympy import factorint

def A002053(n): return next(filter(lambda m:-n==sum(-1 if reduce(ixor, factorint(i).values(), 0)&1 else 1 for i in range(1, m+1)), count(1))) # Chai Wah Wu, Jan 01 2023

STATUS

approved

editing

#25 by Vaclav Kotesovec at Fri Oct 16 10:25:56 EDT 2020

STATUS

editing

approved

#24 by Vaclav Kotesovec at Fri Oct 16 10:25:52 EDT 2020

KEYWORD

nonn,nice,look

STATUS

approved

editing