[go: up one dir, main page]

login
Revision History for A088534 (Bold, blue-underlined text is an addition; faded, red-underlined text is a deletion.)

Showing entries 1-10 | older changes
Number of representations of n by the quadratic form x^2 + xy + y^2 with 0 <= x <= y.
(history; published version)
#54 by N. J. A. Sloane at Mon May 16 17:32:13 EDT 2022
STATUS

proposed

approved

#53 by Michel Marcus at Mon May 16 10:42:56 EDT 2022
STATUS

editing

proposed

#52 by Michel Marcus at Mon May 16 10:42:52 EDT 2022
LINKS

Michel-Marie Deza, Mathieu Dutour Sikiric, and Mikhail Ivanovitch Shtogrin, <a href="https://doi.org/10.1007/978-81-322-2449-5">Geometric Structure of Chemistry-Relevant Graphs</a>, Springer, 2015; see Table 5.4 and Section 5.4.

STATUS

proposed

editing

#51 by Chai Wah Wu at Mon May 16 10:26:39 EDT 2022
STATUS

editing

proposed

#50 by Chai Wah Wu at Mon May 16 10:26:15 EDT 2022
PROG

return c # Chai Wah Wu, May 16 2022

#49 by Chai Wah Wu at Mon May 16 10:26:02 EDT 2022
PROG

(Python)

def A088534(n):

c = 0

for y in range(n+1):

if y**2 > n:

break

for x in range(y+1):

z = x*(x+y)+y**2

if z > n:

break

elif z == n:

c += 1

return c # Chai Wah Wu, May 16 2022

STATUS

approved

editing

#48 by Michael De Vlieger at Thu Dec 23 12:07:48 EST 2021
STATUS

reviewed

approved

#47 by Joerg Arndt at Thu Dec 23 11:59:41 EST 2021
STATUS

proposed

reviewed

#46 by Andrey Zabolotskiy at Thu Dec 23 07:43:04 EST 2021
STATUS

editing

proposed

#45 by Andrey Zabolotskiy at Thu Dec 23 06:46:07 EST 2021
COMMENTS

Also, apparently the number of 6-regular plane graphs with n vertices that have only trigonal faces and loops ("({1,3},6)-spheres" from the paper by Michel Deza and Mathieu Dutour Sikiric). - Andrey Zabolotskiy, Dec 22 2021

LINKS

Oscar Marmon, Michel-Marie Deza, Mathieu Dutour Sikiric, Mikhail Ivanovitch Shtogrin, <a href="httphttps://arxivdoi.org/abs/math10.1007/0508201978-81-322-2449-5">Hexagonal Lattice Points on CirclesGeometric Structure of Chemistry-Relevant Graphs</a>, arXiv:math/0508201 [mathSpringer, 2015; see Table 5.4 and Section 5.NT], 20054.

Oscar Marmon, <a href="https://arxiv.org/abs/math/0508201">Hexagonal Lattice Points on Circles</a>, arXiv:math/0508201 [math.NT], 2005.

FORMULA

a(n) = ceiling(A004016(n)/12) = (A002324(n) + A145377(n)) / 2. - Andrey Zabolotskiy, Dec 23 2021