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.

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A225013 Number of 6Xn 0..1 arrays with rows unimodal and columns nondecreasing.

Original entry on oeis.org

7, 49, 252, 1036, 3612, 11088, 30738, 78354, 186142, 416394, 884236, 1794196, 3497248, 6577474, 11980667, 21201211, 36548573, 61520899, 101320712, 163556776, 259187048, 403770544, 619111172, 935394436, 1393938716, 2050706932
Offset: 1

Views

Author

R. H. Hardin Apr 23 2013

Keywords

Comments

Row 6 of A225010

Examples

			Some solutions for n=3
..0..0..0....0..0..0....0..0..0....0..0..0....0..0..0....0..1..0....1..1..0
..0..1..0....0..0..0....0..1..0....0..0..0....0..0..0....0..1..1....1..1..0
..0..1..0....1..0..0....0..1..1....0..1..0....1..0..0....0..1..1....1..1..0
..0..1..0....1..1..0....0..1..1....0..1..0....1..0..0....0..1..1....1..1..0
..1..1..0....1..1..0....1..1..1....0..1..0....1..0..0....0..1..1....1..1..1
..1..1..1....1..1..0....1..1..1....0..1..0....1..0..0....1..1..1....1..1..1
		

Formula

Empirical: a(n) = (1/479001600)*n^12 + (1/7257600)*n^11 + (187/43545600)*n^10 + (13/161280)*n^9 + (14671/14515200)*n^8 + (3043/345600)*n^7 + (2380201/43545600)*n^6 + (347911/1451520)*n^5 + (8129699/10886400)*n^4 + (923183/604800)*n^3 + (913741/415800)*n^2 + (49/40)*n + 1

A225014 Number of 7Xn 0..1 arrays with rows unimodal and columns nondecreasing.

Original entry on oeis.org

8, 64, 372, 1716, 6672, 22716, 69498, 194634, 505912, 1233584, 2845492, 6251596, 13154948, 26635774, 52097267, 98759971, 181971248, 326703424, 572756312, 982365976, 1651162688, 2723729944, 4415408372, 7042481236, 11063492816
Offset: 1

Views

Author

R. H. Hardin Apr 23 2013

Keywords

Comments

Row 7 of A225010

Examples

			Some solutions for n=3
..1..1..0....0..0..1....0..1..0....1..0..0....0..0..0....0..0..0....0..0..0
..1..1..0....0..0..1....1..1..0....1..0..0....0..1..0....0..0..0....0..1..0
..1..1..0....0..0..1....1..1..0....1..1..0....1..1..0....0..0..0....0..1..0
..1..1..0....0..0..1....1..1..0....1..1..0....1..1..0....0..0..1....1..1..0
..1..1..0....0..0..1....1..1..1....1..1..0....1..1..0....0..0..1....1..1..0
..1..1..0....0..1..1....1..1..1....1..1..1....1..1..1....0..1..1....1..1..0
..1..1..0....0..1..1....1..1..1....1..1..1....1..1..1....1..1..1....1..1..1
		

Formula

Empirical: a(n) = (1/87178291200)*n^14 + (1/958003200)*n^13 + (43/958003200)*n^12 + (103/87091200)*n^11 + (1847/87091200)*n^10 + (7891/29030400)*n^9 + (1560493/609638400)*n^8 + (222427/12441600)*n^7 + (2023297/21772800)*n^6 + (1926401/5443200)*n^5 + (29332549/29937600)*n^4 + (1353853/739200)*n^3 + (183490757/75675600)*n^2 + (363/280)*n + 1

A228510 a(n) = (128*n^4/25+14528*n^3/225+20344*n^2/75+661816*n/1575+168)*(n+6)!/n!.

Original entry on oeis.org

120960, 4682880, 54268416, 364571136, 1758756096, 6759726336, 21978671616, 62815154688, 161990345088, 384087420288, 849090198528, 1768911326208, 3502103394816, 6633368787456, 12086145432576, 21278464551936, 36334471510656, 60366490588800
Offset: 0

Views

Author

Charles A. Lane, Aug 23 2013

Keywords

Comments

Name was "Coefficients from quartic oscillator number 22".
See comment and example in A225010.

Examples

			For n=4 the solution is 1758756096.
		

Crossrefs

Cf. A225010.

Programs

  • Magma
    m:=20; R:=PowerSeriesRing(Integers(), m); Coefficients(R!(1152*(105+2910*x+8168*x^2+4530*x^3+415*x^4)/(1-x)^11)); // Bruno Berselli, Oct 16 2013
  • Mathematica
    Table[(128 n^4/25 + 14528 n^3/225 + 20344 n^2/75 + 661816 n/1575 + 168) (n + 6)!/n!, {n, 0, 20}] (* Bruno Berselli, Oct 16 2013 *)

Formula

G.f.: 1152*(105 +2910*x +8168*x^2 +4530*x^3 +415*x^4)/(1-x)^11. [Bruno Berselli, Oct 16 2013]
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