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A079409 Array T(m,n) (m>=0, n>=0) read by antidiagonals: T(0, 0) = 1, T(0, n) = 0 if n > 0, T(m, n) = T(m-1, n - T(m-1, n)) + T(m-1, n - T(m-1, n-1)) if m > 0. 1
1, 1, 0, 1, 1, 0, 1, 2, 0, 0, 1, 1, 1, 0, 0, 1, 2, 3, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 1, 2, 3, 4, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, 2, 3, 4, 5, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 1, 2, 3, 4, 5, 6, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 5, 6, 7, 0, 0, 0, 0, 0, 0, 0 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,8

COMMENTS

This two-dimensional array is to Pascal's triangle as the Hofstadter Q-sequence A005185 is to Fibonacci's sequence.

Unlike the Hofstadter Q-sequence, it is very regular and admits a simple closed form: T(m, n) = 0 if n > m, T(m, n) = 1 if n <= m and m - n is even, T(m, n) = n + 1 if n <= m and m - n is odd.

LINKS

Table of n, a(n) for n=0..104.

EXAMPLE

For 0 <= m <= 6 and 0 <= n <= 6, the array looks like:

1,0,0,0,0,0,0

1,1,0,0,0,0,0

1,2,1,0,0,0,0

1,1,3,1,0,0,0

1,2,1,4,1,0,0

1,1,3,1,5,1,0

1,2,1,4,1,6,1

CROSSREFS

Cf. A004001, A005185, A007318, A052553, A079408.

Sequence in context: A064559 A067255 A065716 * A114643 A038498 A319510

Adjacent sequences:  A079406 A079407 A079408 * A079410 A079411 A079412

KEYWORD

nonn,tabl

AUTHOR

Rob Arthan, Jan 06 2003

STATUS

approved

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Last modified April 21 20:03 EDT 2019. Contains 322328 sequences. (Running on oeis4.)