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A060021

Maximal size of a subset of any Abelian group of order n that does not contain 0 and fails to span the group nontrivially.

1, 1, 2, 2, 3, 3, 4, 4, 4, 5, 5, 5, 6, 6, 7, 6, 8, 7, 9, 7, 10, 8, 11, 8, 12, 9, 13, 9, 14, 9, 15, 11, 16, 10, 17, 10, 18, 13, 19, 11, 20, 11, 21, 15, 22, 12, 23

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OFFSET

2,3

REFERENCES

J. R. Griggs (griggs(AT)math.sc.edu), personal communication, Apr 24, 2001.

LINKS

Table of n, a(n) for n=2..48.

J. R. Griggs, Spanning subset sums for finite Abelian groups, Discrete Math., 229 (2001), 89-99.

FORMULA

a(2n) = n - 1 for n >= 10 [from Griggs]. - Sean A. Irvine, Oct 22 2022

a(p) = floor(2*sqrt(p-2)) - 1 for prime p >= 3 [from Griggs]. - Sean A. Irvine, Oct 22 2022

CROSSREFS

Cf. A060020.

Sequence in context: A084500 A084557 A024417 * A350029 A000006 A061017

Adjacent sequences: A060018 A060019 A060020 * A060022 A060023 A060024

KEYWORD

nonn,more

AUTHOR

N. J. A. Sloane, Mar 17 2001

EXTENSIONS

a(21)-a(48) from Sean A. Irvine, Oct 22 2022

STATUS

approved

URL: https://oeis.org/A060021

⇱ A060021 - OEIS