A098585 Number of edges in LCM of graphs K_n and C_4.

0, 1, 12, 24, 60, 90, 168, 224, 324, 45, 660, 264, 1092, 546, 1680, 960, 2312, 153, 3420, 760, 4620, 1386, 6072, 2208, 7500, 325, 9828, 1512, 12180, 2610, 14880, 3968, 17424, 561, 21420, 2520, 25308, 4218, 29640, 6240, 33620, 861, 39732, 3784, 45540, 6210, 51888

Offset

0,3

Links

Table of n, a(n) for n=0..46.

P. Adams, D. Bryant and B. Maenhaut, Common multiples of graphs and a 4-cycle, Discrete Math., 275 (2004), 289-297.

Formula

See Maple code.

Maple

f:=proc(n) local i, j; j:=n*(n+1)/2; i := n mod 8; if i = 0 then RETURN((n+1)*j); fi; if i = 1 then RETURN(j); fi; if i = 2 then RETURN((n+2)*j); fi; if i = 3 then RETURN(4*j); fi; if i = 4 then RETURN((n+2)*j); fi; if i = 5 then RETURN(6*j); fi; if i = 6 then RETURN((n+2)*j); fi; if i = 7 then RETURN(8*j); fi; end;

Crossrefs

Sequence in context: A097704 A289132 A348716 * A087105 A230355 A063975

Adjacent sequences: A098582 A098583 A098584 * A098586 A098587 A098588

Keyword

nonn

Author

N. J. A. Sloane, Nov 04 2004

Status

approved