The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A048259 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A048259

Number of distinct solutions to x + y + z = 0 (mod n), where two solutions are equivalent if one can be obtained from the other by multiplying by units in Z/nZ and permuting x,y,z.
(history; published version)

#15 by N. J. A. Sloane at Fri Jun 11 18:31:53 EDT 2021

STATUS

proposed

approved

#14 by Andrew Howroyd at Fri Jun 11 15:41:10 EDT 2021

STATUS

editing

proposed

#13 by Andrew Howroyd at Fri Jun 11 15:39:50 EDT 2021

PROG

(PARI)

iscanon(n, v)={for(d=1, n-1, if(gcd(n, d)==1 && lex(v, vecsort(v*d%n))>0, return(0))); 1}

a(n)={if(n==0, 1, sum(x=0, n-1, sum(y=x, n-1, my(z=(-x-y)%n); y<=z && iscanon(n, [x, y, z]) )))} \\ Andrew Howroyd, Jun 11 2021

STATUS

proposed

editing

Discussion

Fri Jun 11

15:41

Andrew Howroyd: I agree independently.

#12 by Felix Fröhlich at Fri Jun 11 07:52:00 EDT 2021

STATUS

editing

proposed

#11 by Felix Fröhlich at Fri Jun 11 07:51:54 EDT 2021

CROSSREFS

Cf. A007997, A007998, A003050, A003051.

STATUS

proposed

editing

#10 by Sean A. Irvine at Thu Jun 10 22:28:03 EDT 2021

STATUS

editing

proposed

#9 by Sean A. Irvine at Thu Jun 10 22:25:16 EDT 2021

DATA

1, 1, 2, 3, 4, 3, 7, 4, 8, 6, 8, 4, 15, 5, 10, 11, 14, 5, 17, 6, 18, 14, 12, 6, 31, 9, 14, 13, 22, 7, 33, 8, 24, 16, 16, 16, 39, 9, 18, 19, 38, 9, 42, 41, 10, 28, 29, 28, 20, 10, 58, 57, 15, 30, 22, 21, 32, 11, 44, 43, 20, 47, 25, 46, 24, 24, 12, 79, 77, 13, 26, 36, 43, 35, 42, 23, 54, 53, 14, 39, 27, 55, 38, 26, 52, 14, 8583

LINKS

Sean A. Irvine, <a href="https://github.com/archmageirvine/joeis/blob/master/src/irvine/oeis/a048/A048259.java">Java program</a> (github)

EXTENSIONS

a(42) onward corrected by Sean A. Irvine, Jun 10 2021

STATUS

approved

editing

Discussion

Thu Jun 10

22:28

Sean A. Irvine: Can someone please make an independent check of the data change?  It is possible I have a bug or misunderstanding of what this sequence is.

#8 by Joerg Arndt at Sat Mar 07 01:13:15 EST 2020

STATUS

reviewed

approved

#7 by Michel Marcus at Sat Mar 07 00:45:43 EST 2020

STATUS

proposed

reviewed

#6 by Jon E. Schoenfield at Sat Mar 07 00:05:04 EST 2020

STATUS

editing

proposed