A240769 - OEIS

A240769

Triangle read by rows: T(1,1) = 1; T(n+1,k) = T(n,k+1), 1 <= k < n; T(n+1,n) = 2*T(n,1); T(n+1,n+1) = 2*T(n,1) - 1.

1, 2, 1, 1, 4, 3, 4, 3, 2, 1, 3, 2, 1, 8, 7, 2, 1, 8, 7, 6, 5, 1, 8, 7, 6, 5, 4, 3, 8, 7, 6, 5, 4, 3, 2, 1, 7, 6, 5, 4, 3, 2, 1, 16, 15, 6, 5, 4, 3, 2, 1, 16, 15, 14, 13, 5, 4, 3, 2, 1, 16, 15, 14, 13, 12, 11, 4, 3, 2, 1, 16, 15, 14, 13, 12, 11, 10, 9, 3, 2

(list; table; graph; refs; listen; history; text; internal format)

OFFSET

1,2

COMMENTS

Let h be the initial term of row n, to get row n+1, remove h and then append 2*h and 2*h+1;

A080079(n) = T(n,1); T(n,T(n,1)) = 1.

LINKS

Reinhard Zumkeller, Rows n = 1..128 of triangle, flattened

EXAMPLE

. 1: 1

. 2: 2 1

. 3: 1 4 3

. 4: 4 3 2 1

. 5: 3 2 1 8 7

. 6: 2 1 8 7 6 5

. 7: 1 8 7 6 5 4 3

. 8: 8 7 6 5 4 3 2 1

. 9: 7 6 5 4 3 2 1 16 15

. 10: 6 5 4 3 2 1 16 15 14 13

. 11: 5 4 3 2 1 16 15 14 13 12 11

. 12: 4 3 2 1 16 15 14 13 12 11 10 9 .

PROG

(Haskell)

a240769 n k = a240769_tabl !! (n-1) !! (k-1)

a240769_row n = a240769_tabl !! (n-1)

a240769_tabl = iterate (\(x:xs) -> xs ++ [2*x, 2*x-1]) [1]

CROSSREFS

Cf. A062383 (row maxima).

Sequence in context: A225924 A078015 A366781 * A357320 A174455 A245596

Adjacent sequences: A240766 A240767 A240768 * A240770 A240771 A240772

KEYWORD

nonn,tabl,look

AUTHOR

Reinhard Zumkeller, Apr 13 2014

STATUS

approved