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A028311 Odd numbers k such that {1..k-1} can be partitioned into disjoint sets I, J with 2I == -J (mod k) such that I, J are unions of cyclotomic cosets mod k. 2
5, 7, 13, 17, 23, 25, 29, 31, 35, 37, 41, 47, 49, 53, 61 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..15.

Sean A. Irvine, Java program (github)

F. J. MacWilliams, A. M. Odlyzko, N. J. A. Sloane and H. N. Ward, Self-Dual Codes over GF(4), J. Combin. Theory, A 25 288-318 1978.

CROSSREFS

Cf. A028312.

Sequence in context: A342705 A314321 A314322 * A335075 A240716 A216773

Adjacent sequences:  A028308 A028309 A028310 * A028312 A028313 A028314

KEYWORD

nonn,more

AUTHOR

N. J. A. Sloane

EXTENSIONS

a(11)-a(15) from Sean A. Irvine, Jan 11 2020

STATUS

approved

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Last modified September 18 11:01 EDT 2021. Contains 347518 sequences. (Running on oeis4.)