cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A125752 Moessner triangle using the Fibonacci terms.

Original entry on oeis.org

1, 1, 2, 4, 9, 8, 26, 69, 77, 55, 261, 806, 1088, 920, 610, 4062, 14362, 22887, 22856, 17034, 10946, 98912, 395253, 728605, 847832, 721756, 502606, 317811, 3809193, 17008391, 35644614, 47557978, 46166656, 35655012, 23828383, 14930352
Offset: 1

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Author

Gary W. Adamson, Dec 06 2006

Keywords

Comments

A Moessner triangle is generated with the recurrence described in A125714, starting from a first row M(1,c) filled with the Fibonacci numbers M(1,c) = A000045(c), c >= 1.
Subsequent rows n are generated from the numbers in their previous rows with the rule:
Mark/circle all elements M(n-1, A000217(t)) of the previous row n-1, t >= 1.
Define the elements M(n,.) as the partial sums of the M(n-1,.) that have not been marked:
M(n,c) = Sum_{j=1..c} M(n-1,A014132(j)), c >= 1. The T(n,m) are then defined by reading the marked/circled terms "along antidiagonals": T(n,m) = M(n+m-1, A000217(m)), n >= 1, 1 <= m <= n.

Examples

			The upper left corner of the array M(n,c) is
1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, 987, 1597, 2584, ...
1, 4, 9, 22, 43, 77, 166, 310, 543, 920, 1907, 3504, 6088, 10269, 17034, ...
4, 26, 69, 235, 545, 1088, 2995, 6499, 12587, 22856, 57601, 121003, 230773, ...
26, 261, 806, 3801, 10300, 22887, 80488, 201491, 432264, 847832, 2586423, ...
261, 4062, 14362, 94850, 296341, 728605, 3315028, 9488917, 22445416, ...
4062, 98912, 395253, 3710281, 13199198, 35644614, 213010460, 690899755, ...
and dropping the columns with column numbers in A014132, reading the remaining array by antidiagonals leads to the final triangle T(n,m):
    1;
    1,   2;
    4,   9,    8;
   26,  69,   77,  55;
  261, 806, 1088, 920, 610;
  ...
		

References

  • J. H. Conway and R. K. Guy, "The Book of Numbers", Springer-Verlag, 1996, p. 64.

Crossrefs

Formula

T(n,n) = A081667(n-1).

Extensions

More terms from Joshua Zucker, Jun 17 2007
Description of starting row corrected, comments detailed with formulas by R. J. Mathar, Sep 17 2009