OFFSET
1,1
LINKS
Muniru A Asiru, Table of n, a(n) for n = 1..273
Gordon Royle, Numbers of Small Groups
H. U. Besche, B. Eick and E. A. O'Brien. The Small Groups Library
EXAMPLE
The 13 groups of order 56 have the following structure C7 : C8, C56, C7 : Q8, C4 x D14, D56, C2 x (C7 : C4), (C14 x C2) : C2, C28 x C2, C7 x D8, C7 x Q8, (C2 x C2 x C2) : C7, C2 x C2 x D14, C14 x C2 x C2 where C, D and Q mean Cyclic group, Dihedral group and Quarternion group of the stated order. The symbols x and : mean direct and semidirect products respectively.
PROG
(GAP) A292896 := Filtered([1..2015], n -> NumberSmallGroups(n) = 13);
CROSSREFS
Cf. A000001. Cyclic numbers A003277. Numbers m such that there are precisely k groups of order m: A054395 (k=2), A055561 (k=3), A054396 (k=4), A054397 (k=5), A135850 (k=6), A249550 (k=7), A249551 (k=8), A249552 (k=9), A249553 (k=10), A249554 (k=11), A249555 (k=12), this sequence (k=13), A294155 (k=14), A294156 (k=15), A295161 (k=16), A294949 (k=17), A298909 (k=18), A298910 (k=19), A298911 (k=20).
KEYWORD
nonn
AUTHOR
Muniru A Asiru, Oct 23 2017
EXTENSIONS
More terms from Muniru A Asiru, Nov 18 2017
STATUS
approved