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A112498
Third column of second-order Eulerian triangle A008517 divided by 2.
1
3, 29, 164, 726, 2805, 9975, 33630, 109424, 347519, 1085313, 3349848, 10253994, 31203945, 94561643, 285716018, 861472836, 2593592883, 7800176565, 23441423340, 70410252350, 211411111133, 634610819679, 1904620987014
OFFSET
3,1
COMMENTS
See A004301 for the doubled sequence.
FORMULA
a(n)=A008517(n, 3)/2.
G.f.: x^3*(3-x-6*x^2)/(((1-x)^3)*((1-2*x)^2)*(1-3*x)). See the comment on column g.f.s under A008517.
a(n) = 3*a(n-1) + (2*n-3)*(2^(n-1)-n), n>3, with a(3)=3.
a(n)= 3*A112502(n-3) - A112502(n-4) - 6*A112502(n-5), n>=5.
CROSSREFS
Cf. A000295 (one half of second column).
Sequence in context: A094809 A096028 A137786 * A227694 A118584 A126185
KEYWORD
nonn,easy
AUTHOR
Wolfdieter Lang, Oct 14 2005
STATUS
approved