A060924 Bisection of Lucas triangle A060922: odd-indexed members of column sequences of A060922 (not counting leading zeros).

3, 7, 6, 18, 38, 9, 47, 158, 120, 12, 123, 566, 753, 280, 15, 322, 1880, 3612, 2568, 545, 18, 843, 5964, 15040, 16220, 7043, 942, 21, 2207, 18342, 57366, 83780, 57560, 16536, 1498, 24, 5778, 55162, 206115

Offset

0,1

Comments

Row sums give A060927. Column sequences (without leading zeros) are, for m=0..5: A005248(n+1), 2*A061171, A061172, 4*A061173, A061174, 2*A061175.

Companion triangle A060923 (even part).

Links

Table of n, a(n) for n=0..38.

Formula

a(n, m) = A060922(2*n+1-m, m).

a(n, m) = ((2*n-m+1)*A060923(n, m-1) + 2*(2*(2*n+1)-3*m)*a(n-1, m-1) + 4*(2*n-m)*A060923(n-1, m-1))/(5*m), m >= n >= 1; a(n, 0) = A005248(n); otherwise 0.

G.f. for column m >= 0: x^m*pLo(m+1, x)/(1-3*x+x^2)^(m+1), where pLo(n, x) := Sum_{m=0..n+floor((n-1)/2)} A061187(n-1, m)*x^m are the row polynomials of the (signed) staircase A061187.

T(n,k) = 3*T(n-1,k) + 2*T(n-1,k-1) - T(n-2,k) + 2*T(n-2,k-1) - T(n-2,k-2) + 4*T(n-3,k-2), T(0,0) = 3, T(1,0) = 7, T(1,1) = 6, T(2,0) = 18, T(2,1) = 38, T(2,2) = 9, T(n,k) = 0 if k < 0 or if k > n. - Philippe Deléham, Jan 21 2014

Example

{3}; {7,6}; {18,38,9}; {47,158,120,12}; ...; pLo(2,x)= 2*(3+x-2*x^2).

Crossrefs

Cf. A005248.

Sequence in context: A217112 A241016 A245602 * A365100 A213931 A213401

Adjacent sequences: A060921 A060922 A060923 * A060925 A060926 A060927

Keyword

nonn,easy,tabl

Author

Wolfdieter Lang, Apr 20 2001

Status

approved