Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #11 Sep 08 2022 08:45:13
%S 1,2,18,206,3690,91742,2493738,63266366,1449722250,30406367582,
%T 595643428458,11087927110526,198731319099210,3462982712427422,
%U 59088178966503978,992435464713354686,16472174763523362570,270964491631927159262,4427273424527020664298
%N Number of ordered 4-multiantichains on an n-set.
%H G. C. Greubel, <a href="/A092882/b092882.txt">Table of n, a(n) for n = 0..825</a>
%F 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.
%F 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
%t 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 *)
%o (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
%o (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
%Y Cf. A092880, A092881, A092883, A092884.
%K nonn,easy
%O 0,2
%A Goran Kilibarda, _Vladeta Jovovic_, Mar 10 2004
%E More terms from _Colin Barker_, Jul 11 2013