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

A245945 Number of length n+3 0..2 arrays with some pair in every consecutive four terms totalling exactly 2.

Original entry on oeis.org

71, 197, 545, 1501, 4145, 11441, 31577, 87161, 240581, 664051, 1832917, 5059221, 13964475, 38544783, 106391413, 293661867, 810566283, 2237327253, 6175476757, 17045567707, 47049222251, 129865390965, 358454804639, 989407924729
Offset: 1

Views

Author

R. H. Hardin, Aug 08 2014

Keywords

Examples

			Some solutions for n=8:
..0....1....1....1....2....1....0....0....1....1....2....1....0....0....1....2
..1....1....2....1....0....2....2....1....0....2....0....0....0....1....1....0
..2....2....0....2....1....0....2....0....2....2....0....1....2....1....0....0
..0....1....0....0....1....1....0....2....0....1....2....2....0....0....1....1
..1....2....1....1....1....0....2....1....0....0....2....1....1....2....1....2
..0....1....1....0....1....1....2....0....1....1....0....0....0....2....1....1
..2....2....1....2....2....1....1....0....1....2....2....1....1....1....2....0
..2....0....1....2....1....0....0....1....0....2....0....0....2....0....1....2
..0....1....0....0....2....0....1....1....0....0....2....2....0....2....2....0
..0....1....1....1....0....2....1....2....2....2....2....1....2....0....1....0
..2....2....1....1....0....2....2....1....2....1....1....0....0....0....2....2
		

Crossrefs

Column 2 of A245950.

Formula

Empirical: a(n) = 2*a(n-1) + 2*a(n-2) + a(n-3) - a(n-4) - 2*a(n-5) - 2*a(n-6) - a(n-7) + a(n-8) + a(n-9).
Empirical g.f.: x*(71 + 55*x + 9*x^2 - 54*x^3 - 73*x^4 - 57*x^5 - 15*x^6 + 36*x^7 + 27*x^8) / ((1 - x)*(1 - x - 3*x^2 - 4*x^3 - 3*x^4 - x^5 + x^6 + 2*x^7 + x^8)). - Colin Barker, Nov 05 2018

A245946 Number of length n+3 0..4 arrays with some pair in every consecutive four terms totalling exactly 4.

Original entry on oeis.org

453, 1889, 7769, 31465, 128649, 525041, 2141609, 8740385, 35666177, 145538749, 593901081, 2423511809, 9889552885, 40356071813, 164679993617, 672005573917, 2742236755101, 11190178304945, 45663487141625, 186337877072653
Offset: 1

Views

Author

R. H. Hardin, Aug 08 2014

Keywords

Comments

Column 4 of A245950.

Examples

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

Crossrefs

Cf. A245950.

Formula

Empirical: a(n) = 3*a(n-1) +5*a(n-2) +3*a(n-3) -10*a(n-4) -37*a(n-5) -48*a(n-6) -37*a(n-7) +83*a(n-8) +143*a(n-9) +5*a(n-10) -11*a(n-11) -41*a(n-12) -10*a(n-13) -2*a(n-14) +3*a(n-15).

A245947 Number of length n+3 0..5 arrays with some pair in every consecutive four terms totalling exactly 5.

Original entry on oeis.org

834, 3966, 18384, 82968, 381222, 1744494, 7972932, 36489120, 166920402, 763564758, 3493201536, 15980209872, 73104350502, 334430964150, 1529917916484, 6998905422984, 32017855579074, 146471872453902, 670063969035792
Offset: 1

Views

Author

R. H. Hardin, Aug 08 2014

Keywords

Examples

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

Crossrefs

Column 5 of A245950.

Formula

Empirical: a(n) = 3*a(n-1) + 5*a(n-2) + 13*a(n-3) - 13*a(n-4) - a(n-5) - 3*a(n-6) + a(n-7).
Empirical g.f.: 6*x*(139 + 244*x + 386*x^2 - 476*x^3 - 53*x^4 - 102*x^5 + 36*x^6) / (1 - 3*x - 5*x^2 - 13*x^3 + 13*x^4 + x^5 + 3*x^6 - x^7). - Colin Barker, Nov 05 2018

A245948 Number of length n+3 0..6 arrays with some pair in every consecutive four terms totalling exactly 6.

Original entry on oeis.org

1435, 7669, 39721, 199141, 1021225, 5208673, 26526337, 135336793, 690045061, 3518298991, 17940920173, 91480646389, 466463146399, 2378531818147, 12128251046821, 61842638080231, 315339231002215, 1607932492222021
Offset: 1

Views

Author

R. H. Hardin, Aug 08 2014

Keywords

Comments

Column 6 of A245950.

Examples

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

Crossrefs

Cf. A245950.

Formula

Empirical: a(n) = 4*a(n-1) +8*a(n-2) +2*a(n-3) -39*a(n-4) -139*a(n-5) -175*a(n-6) -179*a(n-7) +980*a(n-8) +1638*a(n-9) -1266*a(n-10) -210*a(n-11) -352*a(n-12) +123*a(n-13) +24*a(n-14) +19*a(n-15) -5*a(n-16).

A245949 Number of length n+3 0..7 arrays with some pair in every consecutive four terms totalling exactly 7.

Original entry on oeis.org

2216, 13064, 73728, 397504, 2217096, 12257032, 67596992, 373997376, 2066660136, 11420014856, 63122102528, 348845096320, 1927940409608, 10655229621512, 58887811241024, 325454196462720, 1798683415254952, 9940745874984456
Offset: 1

Views

Author

R. H. Hardin, Aug 08 2014

Keywords

Examples

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

Crossrefs

Column 7 of A245950.

Formula

Empirical: a(n) = 3*a(n-1) + 9*a(n-2) + 31*a(n-3) - 19*a(n-4) - 3*a(n-5) - 5*a(n-6) + a(n-7).
Empirical g.f.: 8*x*(277 + 802*x + 1824*x^2 - 1244*x^3 - 231*x^4 - 312*x^5 + 64*x^6) / (1 - 3*x - 9*x^2 - 31*x^3 + 19*x^4 + 3*x^5 + 5*x^6 - x^7). - Colin Barker, Nov 05 2018

A245951 Number of length 1+3 0..n arrays with some pair in every consecutive four terms totalling exactly n.

Original entry on oeis.org

14, 71, 196, 453, 834, 1435, 2216, 3305, 4630, 6351, 8364, 10861, 13706, 17123, 20944, 25425, 30366, 36055, 42260, 49301, 56914, 65451, 74616, 84793, 95654, 107615, 120316, 134205, 148890, 164851, 181664, 199841, 218926, 239463, 260964, 284005
Offset: 1

Views

Author

R. H. Hardin, Aug 08 2014

Keywords

Examples

			Some solutions for n=10:
..6....5....7...10....6....7....6....0....3....6....1....8....5....1...10....8
..5....7....5....1...10...10....9...10....7....5...10...10....5....5....9....2
..3....6...10....9....4....6....6....8....7....4....9....4....2....5....7....1
..7....4....5....7...10....4....1...10....7....6....5....0....0....2....0....6
		

Crossrefs

Row 1 of A245950.

Formula

Empirical: a(n) = 2*a(n-1) + a(n-2) - 4*a(n-3) + a(n-4) + 2*a(n-5) - a(n-6).
Conjectures from Colin Barker, Nov 05 2018: (Start)
G.f.: x*(14 + 43*x + 40*x^2 + 46*x^3 + 2*x^4 - x^5) / ((1 - x)^4*(1 + x)^2).
a(n) = 1 + 5*n + 3*n^2 + 6*n^3 for n even.
a(n) = 4 + n + 3*n^2 + 6*n^3 for n odd.
(End)

A245952 Number of length 2+3 0..n arrays with some pair in every consecutive four terms totalling exactly n.

Original entry on oeis.org

26, 197, 676, 1889, 3966, 7669, 13064, 21281, 32290, 47621, 67116, 92737, 124166, 163829, 211216, 269249, 337194, 418501, 512180, 622241, 747406, 892277, 1055256, 1241569, 1449266, 1684229, 1944124, 2235521, 2555670, 2911861, 3300896, 3730817
Offset: 1

Views

Author

R. H. Hardin, Aug 08 2014

Keywords

Examples

			Some solutions for n=10:
..3....1....2....0....6....0....7....8....4...10....2....9....9....3....0....3
..9....1....2....3....6....8....0....5....9....5....6....3....2....0....1....2
..1....9...10...10....2....2...10....5....1....6....1....7....0...10....9....8
..1....6....0....0....4....0....9....0....6....5....4....2....8....6....8...10
..1....8...10....2...10....9....6....6....1....5....7....4....1....3...10....2
		

Crossrefs

Row 2 of A245950.

Formula

Empirical: a(n) = 2*a(n-1) + 2*a(n-2) - 6*a(n-3) + 6*a(n-5) - 2*a(n-6) - 2*a(n-7) + a(n-8).
Conjectures from Colin Barker, Nov 05 2018: (Start)
G.f.: x*(26 + 145*x + 230*x^2 + 299*x^3 + 18*x^4 - 141*x^5 - 2*x^6 + x^7) / ((1 - x)^5*(1 + x)^3).
a(n) = 1 + 12*n - 5*n^2 + 18*n^3 + 3*n^4 for n even.
a(n) = 16 - 5*n - 6*n^2 + 18*n^3 + 3*n^4 for n odd.
(End)

A245953 Number of length 3+3 0..n arrays with some pair in every consecutive four terms totalling exactly n.

Original entry on oeis.org

48, 545, 2304, 7769, 18384, 39721, 73728, 130193, 211440, 332561, 496128, 723625, 1017744, 1407449, 1895424, 2519201, 3281328, 4228993, 5364480, 6745721, 8374608, 10320905, 12585984, 15252529, 18321264, 21888881, 25955328, 30632393, 35919120
Offset: 1

Views

Author

R. H. Hardin, Aug 08 2014

Keywords

Examples

			Some solutions for n=8:
..3....4....6....3....2....2....5....0....0....3....1....3....2....6....5....1
..1....3....7....8....8....0....1....1....6....2....8....8....6....3....4....5
..2....4....2....5....7....8....5....4....8....4....0....4....1....6....2....3
..6....5....8....3....1....4....7....7....3....5....6....5....5....5....6....8
..3....1....6....1....8....6....1....6....5....4....6....4....2....2....6....0
..2....7....2....2....1....0....4....2....2....1....2....8....6....1....0....8
		

Crossrefs

Row 3 of A245950.

Formula

Empirical: a(n) = 3*a(n-1) - 8*a(n-3) + 6*a(n-4) + 6*a(n-5) - 8*a(n-6) + 3*a(n-8) - a(n-9).
Conjectures from Colin Barker, Nov 05 2018: (Start)
G.f.: x*(48 + 401*x + 669*x^2 + 1241*x^3 - 851*x^4 - 557*x^5 + 7*x^6 + 3*x^7 - x^8) / ((1 - x)^6*(1 + x)^3).
a(n) = 1 + 26*n - 17*n^2 + 24*n^3 + 21*n^4 + n^5 for n even.
a(n) = 39 - n - 36*n^2 + 24*n^3 + 21*n^4 + n^5 for n odd.
(End)

A245954 Number of length 4+3 0..n arrays with some pair in every consecutive four terms totalling exactly n.

Original entry on oeis.org

88, 1501, 7744, 31465, 82968, 199141, 397504, 754321, 1292440, 2144941, 3335808, 5074681, 7380184, 10560565, 14620288, 19990561, 26650584, 35181181, 45522880, 58435081, 73803928, 92598661, 114633024, 141119665, 171779608, 208104781
Offset: 1

Views

Author

R. H. Hardin, Aug 08 2014

Keywords

Examples

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

Crossrefs

Row 4 of A245950

Formula

Empirical: a(n) = 2*a(n-1) + 3*a(n-2) - 8*a(n-3) - 2*a(n-4) + 12*a(n-5) - 2*a(n-6) - 8*a(n-7) + 3*a(n-8) + 2*a(n-9) - a(n-10).
Conjectures from Colin Barker, Nov 05 2018: (Start)
G.f.: x*(88 + 1325*x + 4478*x^2 + 12178*x^3 + 8990*x^4 + 2708*x^5 - 310*x^6 - 658*x^7 + 2*x^8 - x^9) / ((1 - x)^6*(1 + x)^4).
a(n) = 1 + 34*n + 6*n^2 - 16*n^3 + 66*n^4 + 15*n^5 for n even.
a(n) = 58 + 57*n - 80*n^2 - 28*n^3 + 66*n^4 + 15*n^5 for n odd.
(End)

A245955 Number of length 5+3 0..n arrays with some pair in every consecutive four terms totalling exactly n.

Original entry on oeis.org

162, 4145, 26244, 128649, 381222, 1021225, 2217096, 4555697, 8345130, 14757441, 24276492, 38959225, 59493294, 89187449, 128950032, 183778785, 254805426, 349227217, 468384660, 622261481, 812372022, 1052152905, 1343233944
Offset: 1

Views

Author

R. H. Hardin, Aug 08 2014

Keywords

Comments

Row 5 of A245950

Examples

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

Formula

Empirical: a(n) = 2*a(n-1) +4*a(n-2) -10*a(n-3) -5*a(n-4) +20*a(n-5) -20*a(n-7) +5*a(n-8) +10*a(n-9) -4*a(n-10) -2*a(n-11) +a(n-12)
Showing 1-10 of 12 results. Next