login
This site is supported by donations to The OEIS Foundation.

 

Logo

Annual Appeal: Please make a donation (tax deductible in USA) to keep the OEIS running. Over 5000 articles have referenced us, often saying "we discovered this result with the help of the OEIS".

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A185508 Third accumulation array, T, of the natural number array A000027, by antidiagonals. 6

%I

%S 1,5,6,16,29,21,41,89,99,56,91,219,295,259,126,182,469,705,755,574,

%T 252,336,910,1470,1765,1645,1134,462,582,1638,2786,3605,3780,3206,

%U 2058,792,957,2778,4914,6706,7595,7266,5754,3498,1287,1507,4488,8190,11634,13916,14406,12894,9690,5643,2002,2288,6963,13035,19110,23814,26068,25284,21510,15510,8723,3003,3367,10439,19965,30030,38640,44100

%N Third accumulation array, T, of the natural number array A000027, by antidiagonals.

%C See A144112 (and A185506) for the definition of accumulation array (aa). A185508=aa(aa(aa(A000027))).

%C Column 1: A000389.

%F T(n,k) = F*(4n^2 + (5k+23)n + 4k^2 + 3k+41), where F = k(k+1)(k+2)n(n+1)(n+2)/2880.

%e Northwest corner:

%e 1 5 16 41 91 182

%e 6 29 89 219 469 910

%e 21 99 295 705 1470 2786

%e 56 259 755 1765 3605 6706

%t h[n_,k_]:=k(k+1)(k+2)n(n+1)(n+2)*(4n^2+(5k+23)n+4k^2+3k+41)/2880;

%t TableForm[Table[h[n,k],{n,1,10},{k,1,15}]]

%t Table[h[n-k+1,k],{n,14},{k,n,1,-1}]//Flatten

%Y Cf. A000027, A185506, A185507, A185509.

%K nonn,tabl

%O 1,2

%A _Clark Kimberling_, Jan 29 2011

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified December 10 21:23 EST 2016. Contains 279011 sequences.