The OEIS is supported by the many generous donors to the OEIS Foundation.

Clique number of commuting graph of alternating group A_n.

0

`%I #6 Jul 26 2013 15:54:28
`

`%S 0,0,0,2,3,4,8,11,15,26,35,47,80,107,143,242,323,431,728,971,1295,
`

`%T 2186,2915,3887,6560,8747,11663,19682,26243,34991,59048,78731,104975,
`

`%U 177146,236195,314927,531440,708587,944783,1594322,2125763,2834351,4782968,6377291,8503055,14348906
`

`%N Clique number of commuting graph of alternating group A_n.
`

`%C The graph is empty for n = 0, 1 and 2, so a(n) = 0 by convention (or should it be 1?).
`

`%D A. Iranmanesh and A. Jafarzadeh, On the commuting graph associated with the symmetric and alternating groups, J. Algebra and Applic., 7 (2008), 129-146.
`

`%F Conjecture: a(n) = a(n-1)+3*a(n-3)-3*a(n-4) for n>6. G.f.: -x^3*(x^6-x^5+2*x^3-x^2-x-2) / ((x-1)*(3*x^3-1)). - _Colin Barker_, Jul 26 2013
`

`%K nonn
`

`%O 0,4
`

`%A _N. J. A. Sloane_, Mar 07 2008
`