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A135841 A000012 * A135839 as infinite lower triangular matrices. 3
1, 2, 1, 3, 1, 1, 4, 2, 1, 1, 5, 2, 2, 1, 1, 6, 3, 2, 2, 1, 1, 7, 3, 3, 2, 2, 1, 1, 8, 4, 3, 3, 2, 2, 1, 1, 9, 4, 4, 3, 3, 2, 2, 1, 1, 10, 5, 4, 4, 3, 3, 2, 2, 1, 1, 11, 5, 5, 4, 4, 3, 3, 2, 2, 1, 1, 12, 6, 5, 5, 4, 4, 3, 3, 2, 2, 1, 1, 13, 6, 6, 5, 5, 4, 4, 3, 3, 2, 2, 1, 1 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Row sums = A024206: (1, 3, 5, 8, 11, 15, 19, ...).

LINKS

G. C. Greubel, Table of n, a(n) for n = 1..1275

FORMULA

T(1, 1) = 1,  T(n, 1) = n, T(n, n) = 1, T(n, k) = floor((n - k + 2)/2). - G. C. Greubel, Dec 06 2016

EXAMPLE

First few rows of the triangle:

  1;

  2, 1;

  3, 1, 1;

  4, 2, 1, 1;

  5, 2, 2, 1, 1;

  6, 3, 2, 2, 1, 1;

  7, 3, 3, 2, 2, 1, 1;

  ...

MATHEMATICA

T[1, 1] := 1; T[n_, 1] := n; T[n_, n_] := 1; T[n_, k_] := Floor[(n - k + 2)/2]; Table[T[n, k], {n, 1, 15}, {k, 1, n}]//Flatten (* G. C. Greubel, Dec 06 2016 *)

CROSSREFS

Cf. A135839, A024206.

Sequence in context: A141294 A174557 A010766 * A210992 A220484 A174066

Adjacent sequences:  A135838 A135839 A135840 * A135842 A135843 A135844

KEYWORD

nonn,tabl

AUTHOR

Gary W. Adamson, Dec 01 2007

EXTENSIONS

Terms a(56) and beyond from G. C. Greubel, Dec 06 2016

STATUS

approved

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Last modified September 29 06:49 EDT 2022. Contains 357082 sequences. (Running on oeis4.)