A092882 Number of ordered 4-multiantichains on an n-set.

1, 2, 18, 206, 3690, 91742, 2493738, 63266366, 1449722250, 30406367582, 595643428458, 11087927110526, 198731319099210, 3462982712427422, 59088178966503978, 992435464713354686, 16472174763523362570, 270964491631927159262, 4427273424527020664298

Offset

0,2

Links

G. C. Greubel, Table of n, a(n) for n = 0..825

Formula

a(n) = 16^n - 12*12^n + 24*10^n + 4*9^n - 12*8^n + 6*7^n - 72*6^n + 72*5^n + 36*4^n - 72*3^n + 26*2^n.

G.f.: -(1159418880*x^10 -1168935552*x^9 +583922688*x^8 -190907480*x^7 +43558356*x^6 -6961978*x^5 +771571*x^4 -58030*x^3 +2824*x^2 -80*x +1) / ((2*x -1)*(3*x -1)*(4*x -1)*(5*x -1)*(6*x -1)*(7*x -1)*(8*x -1)*(9*x -1)*(10*x -1)*(12*x -1)*(16*x -1)). - Colin Barker, Jul 11 2013

Mathematica

Table[16^n - 12*12^n + 24*10^n + 4*9^n - 12*8^n + 6*7^n - 72*6^n + 72*5^n + 36*4^n - 72*3^n + 26*2^n, {n, 0, 50}] (* G. C. Greubel, Oct 06 2017 *)

Prog

(PARI) for(n=0, 50, print1(16^n - 12*12^n + 24*10^n + 4*9^n - 12*8^n + 6*7^n - 72*6^n + 72*5^n + 36*4^n - 72*3^n + 26*2^n, ", ")) \\ G. C. Greubel, Oct 06 2017
(Magma) [16^n - 12*12^n + 24*10^n + 4*9^n - 12*8^n + 6*7^n - 72*6^n + 72*5^n + 36*4^n - 72*3^n + 26*2^n: n in [0..50]]; // G. C. Greubel, Oct 06 2017

Crossrefs

Cf. A092880, A092881, A092883, A092884.

Sequence in context: A303381 A224881 A369921 * A123855 A121407 A369027

Adjacent sequences: A092879 A092880 A092881 * A092883 A092884 A092885

Keyword

nonn,easy

Author

Goran Kilibarda, Vladeta Jovovic, Mar 10 2004

Extensions

More terms from Colin Barker, Jul 11 2013

Status

approved