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 1-5 of 5 results.

A126652 A 3 X 3 magic square with magic sum 75: the Loh-Shu square A033812 multiplied by 5.

Original entry on oeis.org

40, 5, 30, 15, 25, 35, 20, 45, 10
Offset: 1

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Author

Parthasarathy Nambi, Feb 08 2007

Keywords

Comments

The magic sum is 75. See Figure C.6 in Appendix C in Maya Ahmed's PhD thesis.

Examples

			The magic square is:
  40  5 30
  15 25 35
  20 45 10
		

Crossrefs

Cf. A126653 = 3*A033812.

Formula

a(n) = 5*A033812(n). - M. F. Hasler, Jan 26 2019

Extensions

Edited by M. F. Hasler, Jan 26 2019

A126653 A 3 X 3 magic square with magic sum 45: the Loh-Shu square A033812 multiplied by 3.

Original entry on oeis.org

24, 3, 18, 9, 15, 21, 12, 27, 6
Offset: 1

Views

Author

Parthasarathy Nambi, Feb 08 2007

Keywords

Comments

The magic sum is 45. See Figure C.6 in Appendix C in Maya Ahmed's PhD thesis.

Examples

			The magic square is:
24  3 18
9  15 21
12 27  6
		

Crossrefs

Cf. A126652 for 5*A033812.

Formula

a(n) = 3*A033812(n). - M. F. Hasler, Jan 26 2019

Extensions

Edited by M. F. Hasler, Jan 26 2019

A126648 A 3 X 3 magic square with magic sum 123 and entries congruent to 1 (mod 10): equals 10*A033812 - 9.

Original entry on oeis.org

71, 1, 51, 21, 41, 61, 31, 81, 11
Offset: 1

Views

Author

Parthasarathy Nambi, Feb 08 2007

Keywords

Comments

The magic sum is 123. See Figure C.4 in Appendix C in Maya Ahmed's PhD thesis.

Examples

			The magic square is:
  71  1 51
  21 41 61
  31 81 11
		

Crossrefs

Cf. A033812.

Formula

a(n) = 10*A033812(n) - 9. - M. F. Hasler, Jan 26 2019

Extensions

Edited by M. F. Hasler, Jan 26 2019

A126709 The Loh-Shu 3 x 3 magic square, variant 2.

Original entry on oeis.org

4, 9, 2, 3, 5, 7, 8, 1, 6
Offset: 1

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Author

Parthasarathy Nambi, Feb 12 2007

Keywords

Comments

The magic sum is 15. See Figure 1.2 on page 10 in Maya Ahmed's PhD thesis. This magic square is referred to Loh-Shu magic square and is attributed to the legendary Fu Xi (Fuh-Hi).
Sequence A033812 lists the same magic square with rows in reversed order, i.e., vertically flipped. - M. F. Hasler, Jan 26 2019

Examples

			The magic square is:
  4 9 2
  3 5 7
  8 1 6
		

Crossrefs

A033812 is the same magic square with rows listed in reverse order.
Other magic 3 X 3 squares: A126648, A126652, A126653, A126654.
Larger magic squares: A126647, A126649, A126651, A126650.

Extensions

Edited by M. F. Hasler, Jan 26 2019

A091281 Central term in powers of the Lo-Shu Magic Square as a matrix.

Original entry on oeis.org

1, 5, 91, 1125, 17259, 253125, 3806091, 56953125, 854518059, 12814453125, 192222105291, 2883251953125, 43248906698859, 648731689453125, 9730978399444491, 145964630126953125, 2189469525287839659, 32842041778564453125, 492630628439671823691, 7389459400177001953125
Offset: 0

Views

Author

Gary W. Adamson, Dec 28 2003

Keywords

Comments

a(n)/a(n-1) tends to 15, the "Magic Number" of the Lo-Shu Magic Square.
There are a total of 8 variations of the Lo-Shu magic square by rotations and/or reflections. Four of the variations (those with 4, 5, 6 or 6, 5, 4 in the diagonal), have a(2) = 91. The other 4 variations (those with 2, 5, 8 or 8, 5, 2 in the diagonal - lower left to upper right) have a(2) = 59, but otherwise, a(n) for the latter sequence (central term in analogous powers of those matrices) = A091281(n).

Examples

			a(2) = 91 since M^2 = [91, 67, 67 / 67, 91, 67 / 67, 67, 91].
		

Crossrefs

Cf. A033812.

Programs

Formula

The Lo-Shu magic square square as a 3 X 3 matrix is: [8, 1, 6 / 3, 5, 7 / 4, 9, 2] = M. Then a(n) = central term in M^n.
a(2*k+1) = 5*15^(2*k). E.g. a(5) = 253125 = 5*15^4.
a(n) = (1/69)*(23*15^n - 2*24^floor((n+1)/2) + 2*24^floor((n+2)/2)). - Ralf Stephan, Dec 02 2004
G.f.: -(8*x^2+10*x-1) / ((15*x-1)*(24*x^2-1)). - Colin Barker, Dec 10 2012

Extensions

a(12)-a(19) from Charles R Greathouse IV, Dec 14 2011
Showing 1-5 of 5 results.