A017125 Table read by antidiagonals of Fibonacci-type sequences.

0, 1, 1, 1, 1, 2, 2, 2, 1, 3, 3, 3, 3, 1, 4, 5, 5, 4, 4, 1, 5, 8, 8, 7, 5, 5, 1, 6, 13, 13, 11, 9, 6, 6, 1, 7, 21, 21, 18, 14, 11, 7, 7, 1, 8, 34, 34, 29, 23, 17, 13, 8, 8, 1, 9, 55, 55, 47, 37, 28, 20, 15, 9, 9, 1, 10, 89, 89, 76, 60, 45, 33, 23, 17, 10, 10, 1, 11, 144, 144, 123, 97, 73

Offset

0,6

Links

Table of n, a(n) for n=0..82.

Formula

T(n, k) = T(n, k-1)+T(n, k-2) [with T(n, 0) = n and T(n, 1) = 1] = 2*T(n-1, k)-T(n-2, k) = Fib(k)+n*Fib(k-1) = (s^k*(1+2n/s)-t^k*(1+2n/t))/(2^k*sqrt(5)) where s = (1+sqrt(5))/2 and t = (1-sqrt(5))/2 = 1-s.

G.f. for n-th row: (n+x-nx)/(1-x-x^2).

Crossrefs

Rows are (essentially) A000045, A000045, A000032, A000285, A022095, A022096, A022097, etc. Columns are (essentially) A001477, A000012, A000027, A005408, A016789, A016885, etc. One of the diagonals is A007502.

Antidiagonal sums are in A019274.

Sequence in context: A060610 A352671 A351581 * A063276 A352682 A374578

Adjacent sequences: A017122 A017123 A017124 * A017126 A017127 A017128

Keyword

easy,nonn,tabl

Author

Henry Bottomley, Jul 31 2000

Status

approved