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A125512 Array x read by diagonals, where x(i,j) = floor((T(i,j-1)+T(i,j+1))/2) for i>=0 and j>=0. Here T is Wythoff's array A035513. 0
1, 2, 5, 3, 7, 7, 5, 12, 11, 10, 9, 20, 18, 16, 14, 14, 32, 29, 27, 22, 16, 23, 52, 47, 43, 36, 25, 19, 38, 85, 76, 70, 58, 41, 31, 21, 61, 137, 123, 114, 94, 67, 50, 34, 25, 99, 222, 199, 184, 152, 108, 81, 56, 40, 28, 161, 360, 322, 298, 246, 175, 132, 90, 65, 45 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

x(i,j)*(x(i,j) + (T(i,j) mod 2)) = (5*T(i,j)^2 - (T(i,j) mod 2))/4 + A(i)*(-1)^j, where A(i)=A022344(i).

LINKS

Table of n, a(n) for n=0..64.

FORMULA

For j>1, x(i,j) = x(i,j-1) + x(i,j-2) + (T(i,j-1)*T(i,j-2) mod 2).

EXAMPLE

x(2,4)=floor((T(2,3)+T(2,5))/2)=floor((26+68)/2)=47. Since T(2,4)=42 and A(2)=4, the equation in the first comment becomes 47*(47+0) = (5*42^2-0)/4 + 4*(-1)^4.

MATHEMATICA

T[i_, j_]:=i*Fibonacci[j+1]+Fibonacci[j+2]*Floor[(i+1)(1+Sqrt[5])/2]; x[i_, j_]:=Floor[(T[i, j-1]+T[i, j+1])/2]

CROSSREFS

Cf. A035513, A022344.

Sequence in context: A181184 A078383 A232644 * A272908 A191432 A135587

Adjacent sequences:  A125509 A125510 A125511 * A125513 A125514 A125515

KEYWORD

nonn,tabl

AUTHOR

Kenneth J Ramsey, Dec 28 2006

EXTENSIONS

Edited by Dean Hickerson, Jan 14 2007

STATUS

approved

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Last modified January 19 03:54 EST 2020. Contains 331031 sequences. (Running on oeis4.)