This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A208520 Triangle of coefficients of polynomials u(n,x) jointly generated with A208521; see the Formula section. 3
 1, 1, 1, 1, 3, 2, 1, 6, 6, 2, 1, 10, 12, 10, 4, 1, 15, 20, 30, 20, 4, 1, 21, 30, 70, 60, 28, 8, 1, 28, 42, 140, 140, 112, 56, 8, 1, 36, 56, 252, 280, 336, 224, 72, 16, 1, 45, 72, 420, 504, 840, 672, 360, 144, 16, 1, 55, 90, 660, 840, 1848, 1680, 1320, 720, 176 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,5 LINKS FORMULA u(n,x)=u(n-1,x)+x*v(n-1,x), v(n,x)=2x*u(n-1,x)+v(n-1,x)+1, where u(1,x)=1, v(1,x)=1. EXAMPLE First five rows: 1 1...1 1...3...2 1...6...6...2 1...10...12...10...4 First five polynomials u(n,x): 1 1 + x 1 + 3x + 2x^2 1 + 6x + 6x^2 + 2x^3 1 + 10x + 12x^2 + 10x^3 + 4x^4 MATHEMATICA u[1, x_] := 1; v[1, x_] := 1; z = 16; u[n_, x_] := u[n - 1, x] + x*v[n - 1, x]; v[n_, x_] := 2 x*u[n - 1, x] + v[n - 1, x] + 1; Table[Expand[u[n, x]], {n, 1, z/2}] Table[Expand[v[n, x]], {n, 1, z/2}] cu = Table[CoefficientList[u[n, x], x], {n, 1, z}]; TableForm[cu] Flatten[%]    (* A208520 *) Table[Expand[v[n, x]], {n, 1, z}] cv = Table[CoefficientList[v[n, x], x], {n, 1, z}]; TableForm[cv] Flatten[%]    (* A208521 *) CROSSREFS Cf. A208521. Sequence in context: A165958 A113655 A177977 * A114155 A192018 A079513 Adjacent sequences:  A208517 A208518 A208519 * A208521 A208522 A208523 KEYWORD nonn,tabl AUTHOR Clark Kimberling, Feb 28 2012 STATUS approved

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

Last modified October 17 12:56 EDT 2019. Contains 328112 sequences. (Running on oeis4.)