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

A248456 Number of length n+2 0..3 arrays with no three consecutive terms having the sum of any two elements equal to twice the third.

Original entry on oeis.org

48, 148, 460, 1436, 4488, 14040, 43940, 137532, 430508, 1347652, 4218704, 13206360, 41341772, 129418260, 405137308, 1268262348, 3970233208, 12428621208, 38907193300, 121797075276, 381279818252, 1193577924020, 3736437636672
Offset: 1

Views

Author

R. H. Hardin, Oct 06 2014

Keywords

Examples

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

Crossrefs

Column 3 of A248461.

Formula

Empirical: a(n) = 2*a(n-1) + 3*a(n-2) + 4*a(n-3) - 3*a(n-4) - 12*a(n-5) - 4*a(n-6).
Empirical g.f.: 4*x*(12 + 13*x + 5*x^2 - 30*x^3 - 53*x^4 - 16*x^5) / (1 - 2*x - 3*x^2 - 4*x^3 + 3*x^4 + 12*x^5 + 4*x^6). - Colin Barker, Nov 08 2018

A248457 Number of length n+2 0..4 arrays with no three consecutive terms having the sum of any two elements equal to twice the third.

Original entry on oeis.org

96, 380, 1512, 6040, 24160, 96736, 387488, 1552448, 6220480, 24926080, 99883840, 400260160, 1603955712, 6427525312, 25757039296, 103216337152, 413619611968, 1657501354048, 6642119813120, 26617026736320, 106662654436544
Offset: 1

Views

Author

R. H. Hardin, Oct 06 2014

Keywords

Examples

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

Crossrefs

Column 4 of A248461.

Formula

Empirical: a(n) = 3*a(n-1) + 5*a(n-2) + 2*a(n-3) - 16*a(n-4) - 28*a(n-5) - 8*a(n-6).
Empirical g.f.: 4*x*(24 + 23*x - 27*x^2 - 147*x^3 - 186*x^4 - 50*x^5) / ((1 - 2*x)*(1 - x - 7*x^2 - 16*x^3 - 16*x^4 - 4*x^5)). - Colin Barker, Nov 08 2018

A248458 Number of length n+2 0..5 arrays with no three consecutive terms having the sum of any two elements equal to twice the third.

Original entry on oeis.org

174, 862, 4272, 21182, 105026, 520788, 2582406, 12805334, 63497776, 314866606, 1561330890, 7742183252, 38391228334, 190370917646, 943993962960, 4680991358518, 23211674211122, 115099939580084, 570747116572614
Offset: 1

Views

Author

R. H. Hardin, Oct 06 2014

Keywords

Comments

Column 5 of A248461

Examples

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

Formula

Empirical: a(n) = 3*a(n-1) +10*a(n-2) +11*a(n-3) -32*a(n-4) -119*a(n-5) -139*a(n-6) -26*a(n-7) +126*a(n-8) +130*a(n-9) +28*a(n-10) -12*a(n-11) -4*a(n-12)

A248459 Number of length n+2 0..6 arrays with no three consecutive terms having the sum of any two elements equal to twice the third.

Original entry on oeis.org

282, 1652, 9684, 56782, 332940, 1952254, 11447368, 67123652, 393591402, 2307892826, 13532738130, 79351606012, 465292191408, 2728323147524, 15998005845580, 93807139848202, 550054773800480, 3225343557770222
Offset: 1

Views

Author

R. H. Hardin, Oct 06 2014

Keywords

Comments

Column 6 of A248461

Examples

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

Formula

Empirical: a(n) = 5*a(n-1) +4*a(n-2) +20*a(n-3) -58*a(n-4) -109*a(n-5) -155*a(n-6) +28*a(n-7) +295*a(n-8) +175*a(n-9) +153*a(n-10) +36*a(n-11) +382*a(n-12) +183*a(n-13) -193*a(n-14) +140*a(n-15) +96*a(n-16)

A248460 Number of length n+2 0..7 arrays with no three consecutive terms having the sum of any two elements equal to twice the third.

Original entry on oeis.org

432, 2956, 20236, 138534, 948412, 6493036, 44452660, 304332258, 2083523194, 14264241960, 97656029050, 668573914642, 4577199017242, 31336476646048, 214536174915418, 1468760220688680, 10055444434320028, 68841708367472026
Offset: 1

Views

Author

R. H. Hardin, Oct 06 2014

Keywords

Comments

Column 7 of A248461

Examples

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

Formula

Empirical: a(n) = 6*a(n-1) +9*a(n-2) -2*a(n-3) -109*a(n-4) -203*a(n-5) -4*a(n-6) +520*a(n-7) +1012*a(n-8) +696*a(n-9) +385*a(n-10) +373*a(n-11) -514*a(n-12) -2737*a(n-13) -4627*a(n-14) -3396*a(n-15) -2854*a(n-16) -3670*a(n-17) -2204*a(n-18) -634*a(n-19) -332*a(n-20) -162*a(n-21) -24*a(n-22)

A248462 Number of length 1+2 0..n arrays with no three consecutive terms having the sum of any two elements equal to twice the third.

Original entry on oeis.org

6, 18, 48, 96, 174, 282, 432, 624, 870, 1170, 1536, 1968, 2478, 3066, 3744, 4512, 5382, 6354, 7440, 8640, 9966, 11418, 13008, 14736, 16614, 18642, 20832, 23184, 25710, 28410, 31296, 34368, 37638, 41106, 44784, 48672, 52782, 57114, 61680, 66480, 71526
Offset: 1

Views

Author

R. H. Hardin, Oct 06 2014

Keywords

Examples

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

Crossrefs

Row 1 of A248461.

Formula

Empirical: a(n) = 3*a(n-1) -2*a(n-2) -2*a(n-3) +3*a(n-4) -a(n-5).
Empirical for n mod 12 = 0: a(n) = n^3 + (3/2)*n^2 + 2*n.
Empirical for n mod 12 = 1: a(n) = n^3 + (3/2)*n^2 + 2*n + (3/2).
Empirical g.f.: 6*x*(1 + x^2) / ((1 - x)^4*(1 + x)). - Colin Barker, Nov 08 2018

A248463 Number of length 2+2 0..n arrays with no three consecutive terms having the sum of any two elements equal to twice the third.

Original entry on oeis.org

10, 36, 148, 380, 862, 1652, 2956, 4860, 7642, 11400, 16488, 23044, 31482, 41952, 54956, 70672, 89662, 112128, 138708, 169632, 205610, 246884, 294240, 347960, 408890, 477324, 554196, 639828, 735214, 840700, 957356, 1085556, 1226442
Offset: 1

Views

Author

R. H. Hardin, Oct 06 2014

Keywords

Examples

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

Crossrefs

Row 2 of A248461.

Formula

Empirical: a(n) = 2*a(n-1) - a(n-3) - 2*a(n-5) + 2*a(n-6) + a(n-8) - 2*a(n-10) + a(n-11).
Empirical for n mod 12 = 0: a(n) = n^4 + n^3 + (25/6)*n^2 - (5/3)*n.
Empirical for n mod 12 = 1: a(n) = n^4 + n^3 + (25/6)*n^2 + (4/3)*n + (5/2).
Empirical for n mod 12 = 2: a(n) = n^4 + n^3 + (25/6)*n^2 - (5/3)*n - (4/3).
Empirical for n mod 12 = 3: a(n) = n^4 + n^3 + (25/6)*n^2 + (4/3)*n - (3/2).
Empirical for n mod 12 = 4: a(n) = n^4 + n^3 + (25/6)*n^2 - (5/3)*n.
Empirical for n mod 12 = 5: a(n) = n^4 + n^3 + (25/6)*n^2 + (4/3)*n + (7/6).
Empirical for n mod 12 = 6: a(n) = n^4 + n^3 + (25/6)*n^2 - (5/3)*n.
Empirical for n mod 12 = 7: a(n) = n^4 + n^3 + (25/6)*n^2 + (4/3)*n - (3/2).
Empirical for n mod 12 = 8: a(n) = n^4 + n^3 + (25/6)*n^2 - (5/3)*n - (4/3).
Empirical for n mod 12 = 9: a(n) = n^4 + n^3 + (25/6)*n^2 + (4/3)*n + (5/2).
Empirical for n mod 12 = 10: a(n) = n^4 + n^3 + (25/6)*n^2 - (5/3)*n.
Empirical for n mod 12 = 11: a(n) = n^4 + n^3 + (25/6)*n^2 + (4/3)*n - (17/6).
Empirical g.f.: 2*x*(5 + 8*x + 38*x^2 + 47*x^3 + 69*x^4 + 48*x^5 + 42*x^6 + 17*x^7 + 14*x^8) / ((1 - x)^5*(1 + x)^2*(1 + x^2)*(1 + x + x^2)). - Colin Barker, Nov 08 2018

A248464 Number of length 3+2 0..n arrays with no three consecutive terms having the sum of any two elements equal to twice the third.

Original entry on oeis.org

16, 72, 460, 1512, 4272, 9684, 20236, 37868, 67140, 111104, 177024, 269892, 400040, 574140, 806808, 1107132, 1493952, 1978984, 2586340, 3330852, 4242444, 5338788, 6656352, 8217136, 10064140, 12222784, 14744480, 17659176, 21025952, 24879392
Offset: 1

Views

Author

R. H. Hardin, Oct 06 2014

Keywords

Comments

Row 3 of A248461

Examples

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

Formula

Empirical: a(n) = a(n-1) +a(n-3) -2*a(n-7) +a(n-8) -2*a(n-9) +a(n-10) -a(n-11) +2*a(n-12) +2*a(n-15) -a(n-16) +a(n-17) -2*a(n-18) +a(n-19) -2*a(n-20) +a(n-24) +a(n-26) -a(n-27)
Also a polynomial of degree 5 plus a quadratic quasipolynomial with period 840, the first 12 being:
Empirical for n mod 840 = 0: a(n) = n^5 + (1/2)*n^4 + (20/3)*n^3 - (197/30)*n^2 + (51/5)*n
Empirical for n mod 840 = 1: a(n) = n^5 + (1/2)*n^4 + (20/3)*n^3 - (31/15)*n^2 + (66/5)*n - (33/10)
Empirical for n mod 840 = 2: a(n) = n^5 + (1/2)*n^4 + (20/3)*n^3 - (197/30)*n^2 + (113/15)*n - (152/15)
Empirical for n mod 840 = 3: a(n) = n^5 + (1/2)*n^4 + (20/3)*n^3 - (31/15)*n^2 + (26/5)*n - (1/2)
Empirical for n mod 840 = 4: a(n) = n^5 + (1/2)*n^4 + (20/3)*n^3 - (197/30)*n^2 + (51/5)*n - (12/5)
Empirical for n mod 840 = 5: a(n) = n^5 + (1/2)*n^4 + (20/3)*n^3 - (31/15)*n^2 + (158/15)*n + (1/6)
Empirical for n mod 840 = 6: a(n) = n^5 + (1/2)*n^4 + (20/3)*n^3 - (197/30)*n^2 + (51/5)*n - (24/5)
Empirical for n mod 840 = 7: a(n) = n^5 + (1/2)*n^4 + (20/3)*n^3 - (31/15)*n^2 + (26/5)*n + (67/10)
Empirical for n mod 840 = 8: a(n) = n^5 + (1/2)*n^4 + (20/3)*n^3 - (197/30)*n^2 + (113/15)*n - (4/3)
Empirical for n mod 840 = 9: a(n) = n^5 + (1/2)*n^4 + (20/3)*n^3 - (31/15)*n^2 + (66/5)*n - (9/10)
Empirical for n mod 840 = 10: a(n) = n^5 + (1/2)*n^4 + (20/3)*n^3 - (197/30)*n^2 + (51/5)*n - 8
Empirical for n mod 840 = 11: a(n) = n^5 + (1/2)*n^4 + (20/3)*n^3 - (31/15)*n^2 + (38/15)*n + (41/30)

A248465 Number of length 4+2 0..n arrays with no three consecutive terms having the sum of any two elements equal to twice the third.

Original entry on oeis.org

26, 144, 1436, 6040, 21182, 56782, 138534, 295078, 589916, 1082878, 1900666, 3161064, 5083368, 7857546, 11844802, 17344202, 24892396, 34927864, 48224830, 65403924, 87536430, 115449764, 150581308, 194049230, 247712034, 312987618
Offset: 1

Views

Author

R. H. Hardin, Oct 06 2014

Keywords

Comments

Row 4 of A248461

Examples

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

Formula

Empirical: a(n) = -a(n-1) -a(n-2) +2*a(n-5) +3*a(n-6) +4*a(n-7) +3*a(n-8) +2*a(n-9) -3*a(n-11) -4*a(n-12) -6*a(n-13) -5*a(n-14) -5*a(n-15) +3*a(n-18) +2*a(n-19) +4*a(n-20) +a(n-21) -a(n-23) +2*a(n-25) +2*a(n-26) +5*a(n-27) +3*a(n-28) +5*a(n-29) -5*a(n-32) -3*a(n-33) -5*a(n-34) -2*a(n-35) -2*a(n-36) +a(n-38) -a(n-40) -4*a(n-41) -2*a(n-42) -3*a(n-43) +5*a(n-46) +5*a(n-47) +6*a(n-48) +4*a(n-49) +3*a(n-50) -2*a(n-52) -3*a(n-53) -4*a(n-54) -3*a(n-55) -2*a(n-56) +a(n-59) +a(n-60) +a(n-61)

A248466 Number of length 5+2 0..n arrays with no three consecutive terms having the sum of any two elements equal to twice the third.

Original entry on oeis.org

42, 288, 4488, 24160, 105026, 332940, 948412, 2299356, 5183202, 10554328, 20406996, 37023484, 64595054, 107536496, 173894220, 271712160, 414759462, 616455068, 899198128, 1284256968, 1806180638, 2496566424, 3406477720
Offset: 1

Views

Author

R. H. Hardin, Oct 06 2014

Keywords

Comments

Row 5 of A248461

Examples

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