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A210880 Triangular array U(n,k) of coefficients of polynomials defined in Comments. 2
1, 2, 1, 3, 5, 2, 4, 7, 7, 3, 5, 9, 10, 12, 5, 6, 11, 13, 17, 19, 8, 7, 13, 16, 22, 27, 31, 13, 8, 15, 19, 27, 35, 44, 50, 21, 9, 17, 22, 32, 43, 57, 71, 81, 34, 10, 19, 25, 37, 51, 70, 92, 115, 131, 55, 11, 21, 28, 42, 59, 83, 113, 149, 186, 212, 89, 12, 23, 31, 47 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Polynomials u(n,k) are defined by u(n,x)=x*u(n-1,x)+(x^2)*u(n-2,x)+n*(x+1), where u(1)=1 and u(2,x)=x+2.  The array (U(n,k)) is defined by rows:

u(n,x)=U(n,1)+U(n,2)*x+...+U(n,n-1)*x^(n-1).

In each column, the first number is a Fibonacci number and, with one exception, the difference between each two consecutive terms is a Fibonacci number (see the Formula section).

Alternating row sums: 1,1,0,1,-2,3,-5,8,-13,21,... (signed Fibonacci numbers)

LINKS

Table of n, a(n) for n=1..70.

FORMULA

Column k consists of the partial sums of the following sequence: F(k), F(k+2)+F(k-3), F(k+1), F(k+1), F(k+1),..., where F=000045 (Fibonacci numbers.  That is, U(n+1,k)-U(n,k)=F(k+1) for n>1.

EXAMPLE

First six rows:

1

2...1

3...5....2

4...7....7....3

5...9....10...12...5

6...11...13...17...19...8

First three polynomials u(n,x): 1, 2 + x, 3 + 5x + 2x^2.

MATHEMATICA

u[1, x_] := 1; u[2, x_] := x + 2; z = 14;

u[n_, x_] := x*u[n - 1, x] + (x^2)*u[n - 2, x] + n*(x + 1);

Table[Expand[u[n, x]], {n, 1, z/2}]

cu = Table[CoefficientList[u[n, x], x], {n, 1, z}];

TableForm[cu]

Flatten[%]   (* A210880 *)

CROSSREFS

Cf. A208510, A210881, A210874, A210875.

Sequence in context: A106583 A081450 A248408 * A210867 A019588 A193953

Adjacent sequences:  A210877 A210878 A210879 * A210881 A210882 A210883

KEYWORD

nonn,tabl

AUTHOR

Clark Kimberling, Mar 30 2012

STATUS

approved

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Last modified January 26 20:42 EST 2020. Contains 331288 sequences. (Running on oeis4.)