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A340519
Smallest order of a non-abelian group with a center of order n.
0
6, 8, 18, 16, 30, 24, 42, 32, 54, 40, 66, 48, 78, 56, 90, 64, 102, 72, 114, 80, 126, 88, 138, 96, 150, 104, 162, 112, 174, 120, 186, 128, 198, 136, 210, 144, 222, 152, 234, 160, 246, 168, 258, 176, 270, 184, 282, 192, 294, 200, 306, 208, 318, 216, 330, 224, 342, 232, 354, 240, 366, 248
OFFSET
1,1
COMMENTS
a(n) is 6n if n is odd and 4n if n is even. This is because the groups involved are C(n) X S3 if n is odd, where S3 is the symmetric group of order 6, and C(n/2) X D8 if n is even, where D8 is the dihedral group of order 8 and C(m) is the cyclic group of order m.
By Lagrange's Theorem a(n) is a multiple of n.
MATHEMATICA
Table[If[OddQ[n], 6n, 4n], {n, 100}] (* Harvey P. Dale, Mar 03 2023 *)
CROSSREFS
Equals 2*A106833.
Sequence in context: A270046 A093479 A239396 * A315942 A315943 A315944
KEYWORD
nonn
AUTHOR
Bob Heffernan and Des MacHale, Jan 24 2021; corrected Feb 14 2021
STATUS
approved