The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A274248 Row sums of A273751. 2
 1, 5, 16, 37, 72, 124, 197, 294, 419, 575, 766, 995, 1266, 1582, 1947, 2364, 2837, 3369, 3964, 4625, 5356, 6160, 7041, 8002, 9047, 10179, 11402, 12719, 14134, 15650, 17271, 19000, 20841, 22797, 24872, 27069, 29392, 31844, 34429, 37150, 40011, 43015, 46166 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS G. C. Greubel, Table of n, a(n) for n = 1..1000 Index entries for linear recurrences with constant coefficients, signature (3,-2,-2,3,-1). FORMULA a(n) = (14*n^3 - 3*n^2 + 10*n + 3*mod(n, 2))/24. G.f.: x*(1 + 2*x + 3*x^2 + x^3)/((1 - x)^4*(1 + x)). - Ilya Gutkovskiy, Jun 17 2016 E.g.f.: (1/48)*( -3*exp(-x) + (3 + 42*x + 78*x^2 + 28*x^3)*exp(x) ). - G. C. Greubel, Oct 19 2023 MATHEMATICA (* First program *) T[n_, k_]:= T[n, k]= Which[k==n, n(n-1) + 1, k==n-1, (n-1)^2 + 1, k==1, n + T[n-2, 1], 1 < k < n-1, T[n-1, k+1] + 1, True, 0]; a[n_]:= Sum[T[n, k], {k, 1, n}]; Array[a, 40] (* second program: *) LinearRecurrence[{3, -2, -2, 3, -1}, {1, 5, 16, 37, 72}, 50] (* Vincenzo Librandi, Jun 16 2016 *) PROG (Magma) [(n*(20-6*n+28*n^2) + 3*(1-(-1)^n))/48: n in [1..40]]; // G. C. Greubel, Oct 19 2023 (SageMath) [(n*(20-6*n+28*n^2) + 6*(n%2))/48 for n in range(1, 41)] # G. C. Greubel, Oct 19 2023 CROSSREFS Cf. A002623, A173196 (same recurrence), A273751. Sequence in context: A001210 A264552 A128848 * A188427 A022496 A372403 Adjacent sequences: A274245 A274246 A274247 * A274249 A274250 A274251 KEYWORD nonn AUTHOR Jean-François Alcover and Paul Curtz, Jun 16 2016 STATUS approved

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

Last modified August 14 18:55 EDT 2024. Contains 375166 sequences. (Running on oeis4.)