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.

A257062 T(n,k)=Number of length n 1..(k+1) arrays with every leading partial sum divisible by 2 or 3.

Original entry on oeis.org

1, 2, 2, 3, 4, 2, 3, 7, 6, 2, 4, 9, 18, 11, 3, 4, 16, 27, 45, 20, 4, 5, 18, 64, 81, 113, 33, 4, 6, 27, 81, 256, 243, 284, 59, 5, 7, 35, 141, 364, 1024, 729, 713, 104, 7, 7, 45, 200, 738, 1636, 4096, 2187, 1791, 178, 8, 8, 49, 293, 1149, 3866, 7353, 16384, 6561, 4498, 314, 9
Offset: 1

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Author

R. H. Hardin, Apr 15 2015

Keywords

Comments

Table starts
.1...2.....3.....3.......4.......4........5........6.........7.........7
.2...4.....7.....9......16......18.......27.......35........45........49
.2...6....18....27......64......81......141......200.......293.......343
.2..11....45....81.....256.....364......738.....1149......1905......2401
.3..20...113...243....1024....1636.....3866.....6599.....12387.....16807
.4..33...284...729....4096....7353....20249....37893.....80545....117649
.4..59...713..2187...16384...33048...106056...217603....523733....823543
.5.104..1791..6561...65536..148534...555483..1249592...3405505...5764801
.7.178..4498.19683..262144..667585..2909419..7175812..22143847..40353607
.8.314.11297.59049.1048576.3000456.15238479.41207296.143987445.282475249

Examples

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

Crossrefs

Column 1 is A079398(n+4)
Column 2 is A026385(n+1)
Column 4 is A000244
Column 5 is A000302

Formula

Empirical for column k:
k=1: a(n) = a(n-3) +a(n-4)
k=2: a(n) = a(n-2) +3*a(n-3) +a(n-4)
k=3: a(n) = a(n-1) +3*a(n-2) +2*a(n-3)
k=4: a(n) = 3*a(n-1)
k=5: a(n) = 4*a(n-1)
k=6: a(n) = 4*a(n-1) +2*a(n-2) +a(n-3)
k=7: a(n) = 4*a(n-1) +5*a(n-2) +7*a(n-3) +4*a(n-4)
k=8: a(n) = 4*a(n-1) +8*a(n-2) +11*a(n-3) +3*a(n-4)
k=9: a(n) = 5*a(n-1) +9*a(n-2) +5*a(n-3)
k=10: a(n) = 7*a(n-1)
k=11: a(n) = 8*a(n-1)
k=12: a(n) = 8*a(n-1) +4*a(n-2) +2*a(n-3)
k=13: a(n) = 8*a(n-1) +10*a(n-2) +13*a(n-3) +7*a(n-4)
k=14: a(n) = 8*a(n-1) +15*a(n-2) +19*a(n-3) +5*a(n-4)
k=15: a(n) = 9*a(n-1) +15*a(n-2) +8*a(n-3)
k=16: a(n) = 11*a(n-1)
k=17: a(n) = 12*a(n-1)
k=18: a(n) = 12*a(n-1) +6*a(n-2) +3*a(n-3)
k=19: a(n) = 12*a(n-1) +15*a(n-2) +19*a(n-3) +10*a(n-4)
k=20: a(n) = 12*a(n-1) +22*a(n-2) +27*a(n-3) +7*a(n-4)
k=21: a(n) = 13*a(n-1) +21*a(n-2) +11*a(n-3)
k=22: a(n) = 15*a(n-1)
k=23: a(n) = 16*a(n-1)
Empirical for row n:
n=1: a(n) = a(n-1) +a(n-6) -a(n-7)
n=2: a(n) = a(n-1) +2*a(n-6) -2*a(n-7) -a(n-12) +a(n-13)
n=3: a(n) = a(n-1) +3*a(n-6) -3*a(n-7) -3*a(n-12) +3*a(n-13) +a(n-18) -a(n-19)
n=4: [order 25]
n=5: [order 29]
n=6: [order 37]
n=7: [order 43]
Empirical quasipolynomials for row n:
n=1: polynomial of degree 1 plus a quasipolynomial of degree 0 with period 6
n=2: polynomial of degree 2 plus a quasipolynomial of degree 1 with period 6
n=3: polynomial of degree 3 plus a quasipolynomial of degree 2 with period 6
n=4: polynomial of degree 4 plus a quasipolynomial of degree 3 with period 6
n=5: polynomial of degree 5 plus a quasipolynomial of degree 4 with period 6
n=6: polynomial of degree 6 plus a quasipolynomial of degree 5 with period 6
n=7: polynomial of degree 7 plus a quasipolynomial of degree 6 with period 6