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A059592 Square-full part of n^2 + 1. 9
1, 1, 1, 1, 1, 1, 1, 5, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 5, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 5, 1, 1, 1, 1, 1, 17, 1, 1, 29, 1, 5, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 5, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 5, 1, 13, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 5, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 5, 1, 1, 1, 1, 1, 13, 1, 1, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,8
COMMENTS
Related to period-1 continued fractions [z,z,z,...].
A124808 gives number of numbers m <= n with a(m)=1. - Reinhard Zumkeller, Nov 08
LINKS
Reinhard Zumkeller, Table of n, a(n) for n = 0..1000 (corrected by Sean A. Irvine)
FORMULA
a(n) = A000188(A002522(n)).
a(n)^2 * A059591(n) = n^2 + 1.
EXAMPLE
a(7)=5 since 7^2 + 1 = 50 = 25*2 = (5^2)*2.
PROG
(PARI) a(n) = core(n^2+1, 1)[2]; \\ Michel Marcus, Nov 12 2023
CROSSREFS
Sequence in context: A337337 A119788 A334561 * A295554 A319099 A098087
KEYWORD
easy,nonn
AUTHOR
Marc LeBrun, Jan 25 2001
STATUS
approved

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Last modified March 18 22:56 EDT 2024. Contains 370952 sequences. (Running on oeis4.)