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 1-10 of 12 results. Next

A250554 Number of length n+2 0..1 arrays with the sum of second differences multiplied by some arrangement of +-1 equal to zero.

Original entry on oeis.org

2, 8, 14, 32, 62, 128, 254, 512, 1022, 2048, 4094, 8192, 16382, 32768, 65534, 131072, 262142, 524288, 1048574, 2097152, 4194302, 8388608, 16777214, 33554432, 67108862, 134217728, 268435454, 536870912, 1073741822, 2147483648, 4294967294
Offset: 1

Views

Author

R. H. Hardin, Nov 25 2014

Keywords

Examples

			Some solutions for n=6:
..1....1....0....0....0....0....1....0....1....1....0....1....0....1....0....0
..0....1....1....1....0....0....1....1....0....0....1....1....0....1....1....0
..0....1....1....0....1....1....0....1....1....0....1....1....1....0....0....1
..1....1....0....0....0....0....1....1....0....0....0....1....1....0....0....0
..1....0....1....0....0....1....1....1....0....1....0....0....1....0....1....1
..1....1....0....1....1....0....1....1....1....1....0....0....1....1....0....1
..0....1....0....0....1....0....0....1....0....1....0....0....0....0....0....1
..1....1....1....1....1....0....0....0....1....0....1....0....0....0....1....1
		

Crossrefs

Column 1 of A250561.

Formula

Empirical: a(n) = 2*a(n-1) +a(n-2) -2*a(n-3).
Empirical: a(n) = 2^(n+1) for even n, 2^(n+1)-2 for odd n.
Empirical g.f.: 2*x*(1 + 2*x - 2*x^2) / ((1 - x)*(1 + x)*(1 - 2*x)). - Colin Barker, Nov 14 2018

A250555 Number of length n+2 0..2 arrays with the sum of second differences multiplied by some arrangement of +-1 equal to zero.

Original entry on oeis.org

5, 25, 83, 297, 989, 3113, 9611, 29257, 88503, 266769, 802699, 2412545, 7246311, 21755889, 65301163, 195969945, 588042095, 1764390025, 5293696363, 15882140601, 47648522543, 142949767457, 428857697715, 1286589881041, 3859803210479
Offset: 1

Views

Author

R. H. Hardin, Nov 25 2014

Keywords

Comments

Column 2 of A250561

Examples

			Some solutions for n=6
..2....1....2....0....0....2....0....2....0....2....2....2....1....2....1....0
..1....0....2....2....0....0....2....2....0....2....0....1....0....2....1....0
..2....1....2....1....1....2....2....1....0....0....2....0....1....1....1....2
..1....0....0....0....2....2....0....2....2....2....0....0....0....0....2....2
..1....0....0....0....1....1....0....0....1....1....1....0....0....1....2....0
..1....0....0....0....0....2....0....1....1....2....1....2....1....0....1....2
..2....1....0....1....1....1....2....1....2....2....0....0....1....0....0....2
..1....2....0....1....1....1....0....1....2....0....0....1....0....2....2....2
		

Formula

Empirical: a(n) = 4*a(n-1) +2*a(n-2) -17*a(n-3) -3*a(n-4) +24*a(n-5) +16*a(n-6) -13*a(n-7) -26*a(n-8) +2*a(n-9) +12*a(n-10) for n>15

A250556 Number of length n+2 0..3 arrays with the sum of second differences multiplied by some arrangement of +-1 equal to zero.

Original entry on oeis.org

8, 60, 302, 1516, 7126, 30780, 127586, 518052, 2085808, 8367220, 33513408, 134137736, 536713774, 2147172564, 8589316642, 34358507208, 137436497326, 549750908948, 2199013454674, 8796073430888, 35184332920270, 140737410034420
Offset: 1

Views

Author

R. H. Hardin, Nov 25 2014

Keywords

Comments

Column 3 of A250561.

Examples

			Some solutions for n=6
  3    1    1    0    3    3    3    1    1    1    3    0    1    2    0    2
  2    2    0    0    0    3    0    0    0    2    3    3    1    2    1    2
  3    2    2    1    2    1    0    2    1    2    2    2    3    1    1    2
  2    2    2    3    0    1    0    3    1    2    0    1    3    3    3    0
  1    0    1    2    1    3    1    3    2    2    0    2    1    3    1    1
  0    3    0    1    1    2    3    3    0    2    0    1    3    3    0    2
  3    1    2    0    3    3    3    0    2    1    3    1    0    0    3    2
  2    0    3    0    0    1    0    3    1    2    3    2    2    0    0    2
		

Formula

From Manuel Kauers and Christoph Koutschan, Mar 01 2023: (Start)
Generating function: 2*x*(4 + 2*x - 3*x^2 + 73*x^3 + 115*x^4 - 139*x^5 - 453*x^6 - 1231*x^7 + 38*x^8 + 406*x^9 + 3597*x^10 + 2087*x^11 + 1666*x^12 - 3614*x^13 - 4178*x^14 - 4504*x^15 + 903*x^16 + 1985*x^17 + 4173*x^18 + 403*x^19 - 202*x^20 - 1324*x^21 - 1296*x^22 + 684*x^23 - 300*x^24 + 508*x^25 - 56*x^26 + 32*x^27)/((1 - 4*x)*(1 - 2*x)*(1 - x)^3*(1 + x)^2*(1 + x^2)^2*(1 - 2*x^3)^2).
Recurrence equation: 32*a(n) - 56*a(n + 1) + 28*a(n + 2) - 36*a(n + 3) - 8*a(n + 4) + 84*a(n + 5) - 44*a(n + 6) + 58*a(n + 7) - 73*a(n + 8) - a(n + 9) + 4*a(n + 10) - 8*a(n + 11) + 42*a(n + 12) - 26*a(n + 13) + 12*a(n + 14) - 14*a(n + 15) + 7*a(n + 16) - a(n + 17) = 0 for n>11. (End)

A250557 Number of length n+2 0..4 arrays with the sum of second differences multiplied by some arrangement of +-1 equal to zero.

Original entry on oeis.org

13, 117, 761, 5105, 31525, 177421, 937817, 4803653, 24257725, 121800949, 610147053, 3053493273, 15274472475, 76391277073, 382008613455, 1910192140573, 9551389260819, 47758200502193, 238794678323345, 1193984277090533
Offset: 1

Views

Author

R. H. Hardin, Nov 25 2014

Keywords

Comments

Column 4 of A250561

Examples

			Some solutions for n=6
..0....0....2....0....2....0....1....1....1....2....2....2....1....0....1....0
..3....0....2....2....1....1....0....1....2....0....1....0....0....3....4....0
..4....2....3....0....0....0....2....2....3....0....4....2....4....2....4....4
..4....2....3....1....2....0....4....2....4....2....3....2....4....2....2....4
..3....4....3....2....4....2....2....4....1....0....3....2....4....3....3....0
..4....1....1....2....0....4....1....1....0....3....2....1....1....4....1....1
..1....4....2....3....1....4....1....3....4....1....4....4....0....3....0....0
..2....2....4....3....4....1....2....1....1....3....3....0....3....4....1....0
		

A250562 Number of length 3+2 0..n arrays with the sum of second differences multiplied by some arrangement of +-1 equal to zero.

Original entry on oeis.org

14, 83, 302, 761, 1648, 3125, 5446, 8843, 13662, 20173, 28836, 39973, 54102, 71647, 93210, 119221, 150416, 187305, 230650, 281051, 339378, 406245, 482652, 569257, 667098, 776983, 900018, 1036969, 1189124, 1357341, 1542894, 1746747, 1970290
Offset: 1

Views

Author

R. H. Hardin, Nov 25 2014

Keywords

Comments

Row 3 of A250561

Examples

			Some solutions for n=6
..2....0....5....5....4....3....2....1....1....6....5....4....5....3....2....0
..2....3....6....6....1....3....1....4....3....4....4....6....6....2....2....1
..3....5....2....6....2....3....5....4....5....3....3....4....5....2....4....0
..2....2....0....4....6....0....6....3....1....3....1....4....6....2....4....3
..0....3....1....1....3....0....5....6....3....1....0....6....3....1....4....4
		

Formula

Empirical: a(n) = a(n-1) -a(n-2) +2*a(n-3) +a(n-5) -2*a(n-7) -3*a(n-9) +a(n-10) -a(n-11) +3*a(n-12) +2*a(n-14) -a(n-16) -2*a(n-18) +a(n-19) -a(n-20) +a(n-21)
also a quadratic polynomial plus a linear quasipolynomial with period 60, the first 12 being:
Empirical for n mod 60 = 0: a(n) = (329/216)*n^4 + (4747/1080)*n^3 + (1957/360)*n^2 + (23/30)*n + 1
Empirical for n mod 60 = 1: a(n) = (329/216)*n^4 + (4747/1080)*n^3 + (1957/360)*n^2 + (1853/1080)*n + (251/270)
Empirical for n mod 60 = 2: a(n) = (329/216)*n^4 + (4747/1080)*n^3 + (1957/360)*n^2 + (127/270)*n + (211/270)
Empirical for n mod 60 = 3: a(n) = (329/216)*n^4 + (4747/1080)*n^3 + (1957/360)*n^2 + (337/120)*n + (13/5)
Empirical for n mod 60 = 4: a(n) = (329/216)*n^4 + (4747/1080)*n^3 + (1957/360)*n^2 + (47/270)*n + (283/135)
Empirical for n mod 60 = 5: a(n) = (329/216)*n^4 + (4747/1080)*n^3 + (1957/360)*n^2 + (2173/1080)*n + (35/54)
Empirical for n mod 60 = 6: a(n) = (329/216)*n^4 + (4747/1080)*n^3 + (1957/360)*n^2 + (23/30)*n + (13/10)
Empirical for n mod 60 = 7: a(n) = (329/216)*n^4 + (4747/1080)*n^3 + (1957/360)*n^2 + (2393/1080)*n - (77/135)
Empirical for n mod 60 = 8: a(n) = (329/216)*n^4 + (4747/1080)*n^3 + (1957/360)*n^2 + (127/270)*n + (281/135)
Empirical for n mod 60 = 9: a(n) = (329/216)*n^4 + (4747/1080)*n^3 + (1957/360)*n^2 + (277/120)*n + (33/10)
Empirical for n mod 60 = 10: a(n) = (329/216)*n^4 + (4747/1080)*n^3 + (1957/360)*n^2 + (47/270)*n + (43/54)
Empirical for n mod 60 = 11: a(n) = (329/216)*n^4 + (4747/1080)*n^3 + (1957/360)*n^2 + (2713/1080)*n - (7/135)

A250563 Number of length 4+2 0..n arrays with the sum of second differences multiplied by some arrangement of +-1 equal to zero.

Original entry on oeis.org

32, 297, 1516, 5105, 13732, 31173, 63400, 117749, 204712, 336293, 529072, 800689, 1175088, 1677185, 2338728, 3193293, 4283108, 5649837, 7347520, 9429021, 11959288, 15003857, 18642524, 22951429, 28026324, 33959013, 40858932, 48834549
Offset: 1

Views

Author

R. H. Hardin, Nov 25 2014

Keywords

Comments

Row 4 of A250561

Examples

			Some solutions for n=6
..2....2....5....6....2....4....2....1....2....5....4....3....6....2....0....5
..2....1....4....5....5....6....0....4....2....2....2....6....6....6....2....6
..5....5....4....3....1....2....0....6....5....0....6....2....4....1....0....6
..4....0....2....3....1....2....1....5....1....0....5....0....4....5....0....2
..6....4....3....1....0....3....1....0....1....4....0....2....3....5....0....1
..4....3....6....2....1....1....1....3....1....1....0....5....1....1....2....2
		

A250558 Number of length n+2 0..5 arrays with the sum of second differences multiplied by some arrangement of +-1 equal to zero.

Original entry on oeis.org

18, 200, 1648, 13732, 106362, 744564, 4808120, 29723864, 180290280, 1085927844, 6524507992, 39167586296, 235053968050, 1410450413584, 8463032114236, 50779132943420
Offset: 1

Views

Author

R. H. Hardin, Nov 25 2014

Keywords

Comments

Column 5 of A250561.

Examples

			Some solutions for n=5
..3....5....2....4....5....0....2....0....0....2....1....4....2....5....4....5
..4....2....3....0....0....1....3....3....1....2....3....4....3....4....3....1
..5....1....2....0....2....5....1....5....4....4....1....0....1....0....4....5
..0....3....0....1....0....3....5....3....3....3....2....5....2....0....4....3
..0....2....1....0....4....2....3....4....2....0....1....1....0....5....3....0
..3....4....5....4....5....4....3....3....1....1....1....1....1....3....5....0
..4....5....0....4....0....1....4....0....2....5....1....1....2....4....4....0
		

Crossrefs

Cf. A250561.

A250559 Number of length n+2 0..6 arrays with the sum of second differences multiplied by some arrangement of +-1 equal to zero.

Original entry on oeis.org

25, 321, 3125, 31173, 290909, 2457921, 18934449, 137976845, 980389815, 6899647449, 48392977271, 339018816865, 2373951608191, 16620410187793, 116352541474531
Offset: 1

Views

Author

R. H. Hardin, Nov 25 2014

Keywords

Comments

Column 6 of A250561

Examples

			Some solutions for n=4
..6....5....0....5....6....6....2....3....4....3....4....6....2....6....1....4
..0....6....2....1....4....4....3....1....2....2....6....4....3....4....3....4
..0....6....6....4....0....6....5....1....3....1....0....3....3....1....4....5
..4....1....4....1....0....5....3....4....0....1....6....5....4....1....0....2
..3....1....6....1....4....1....6....6....4....5....1....2....2....6....4....4
..5....2....4....3....6....1....1....4....2....6....3....6....5....4....6....6
		

A250560 Number of length n+2 0..7 arrays with the sum of second differences multiplied by some arrangement of +-1 equal to zero.

Original entry on oeis.org

32, 480, 5446, 63400, 695890, 6924692, 62245658, 522997696, 4258085394, 34261234132, 274598186760, 2198154605100, 17589251301614, 140726940443068
Offset: 1

Views

Author

R. H. Hardin, Nov 25 2014

Keywords

Comments

Column 7 of A250561

Examples

			Some solutions for n=4
..1....5....5....0....4....2....3....6....6....3....2....6....6....3....7....7
..5....4....2....5....3....1....0....2....5....6....4....4....1....2....7....4
..1....3....0....7....3....0....6....4....3....0....5....4....7....5....2....2
..1....6....2....1....0....4....4....1....2....2....0....0....5....0....1....0
..1....7....0....5....2....5....6....4....3....3....3....6....4....1....2....5
..5....2....5....4....5....4....3....2....2....4....7....4....1....0....0....4
		

A250564 Number of length 5+2 0..n arrays with the sum of second differences multiplied by some arrangement of +-1 equal to zero.

Original entry on oeis.org

62, 989, 7126, 31525, 106362, 290909, 695890, 1486139, 2927312, 5373103, 9352712, 15511735, 24776808, 38224089, 57324690, 83749019, 119721620, 167645127, 230722744, 312355167, 416892578, 548957107, 714415336, 919264381
Offset: 1

Views

Author

R. H. Hardin, Nov 25 2014

Keywords

Comments

Row 5 of A250561

Examples

			Some solutions for n=5
..1....1....5....4....0....4....1....3....1....0....3....1....5....1....0....2
..0....4....1....3....5....1....1....2....4....0....0....3....1....2....4....5
..5....5....0....0....5....3....4....2....4....1....0....3....2....5....1....4
..0....2....3....4....1....2....3....2....5....5....4....1....1....3....3....3
..0....2....5....0....2....3....0....4....3....5....0....3....1....5....4....5
..2....5....5....1....0....5....3....1....2....5....5....0....4....1....1....0
..1....0....1....0....1....0....1....2....5....3....4....2....4....2....3....1
		
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