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.

Showing 1-2 of 2 results.

A125751 A Moessner triangle using (1, 2, 1, 2, 1, 2, ...).

Original entry on oeis.org

1, 2, 1, 4, 5, 2, 10, 18, 9, 2, 38, 78, 53, 15, 1, 186, 422, 344, 129, 23, 1, 1106, 2704, 2484, 1123, 268, 32, 2, 7718, 19998, 20080, 10342, 2991, 490, 42, 2, 61662, 167520, 180466, 102700, 34211, 6891, 824, 54, 1, 554330, 1567518, 1789474, 1103206
Offset: 1

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Author

Gary W. Adamson, Dec 06 2006

Keywords

Comments

Circle terms n = 1, 3, 6, 10, ... in the sequence (1, 2, 1, 2, 1, 2, ...). Partial sums of the uncircled terms becomes row 2. Circle the terms in row 2 that are one place offset to the left of the circled row 1 terms. Take partial sums and continue with analogous operations. (Cf. A125714 and "The Book of Numbers", p. 64.)
Left border (1, 2, 4, 10, 38, 186, 1106, 7718, 61662, ...).

Examples

			First few rows of the triangle are:
   1;
   2,  1;
   4,  5,  2;
  10, 18,  9,  2;
  38, 78, 53, 15,  1;
  ...
		

References

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

Crossrefs

Extensions

More terms from Joshua Zucker, Jun 17 2007
Corrected the comment concerning the left border - R. J. Mathar, Sep 17 2009

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

Views

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
Showing 1-2 of 2 results.