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.

A247533 T(n,k)=Number of length n+3 0..k arrays with some disjoint pairs in every consecutive four terms having the same sum.

Original entry on oeis.org

8, 33, 8, 88, 45, 8, 185, 136, 61, 8, 336, 317, 220, 81, 8, 553, 600, 561, 364, 105, 8, 848, 1033, 1124, 1007, 604, 153, 8, 1233, 1616, 2009, 2164, 1823, 1018, 217, 8, 1720, 2409, 3220, 3997, 4228, 3455, 1732, 297, 8, 2321, 3400, 4901, 6584, 8051, 8440, 6495, 2956
Offset: 1

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Author

R. H. Hardin, Sep 18 2014

Keywords

Comments

Table starts
.8..33...88...185....336....553....848....1233....1720....2321....3048....3913
.8..45..136...317....600...1033...1616....2409....3400....4661....6168....8005
.8..61..220...561...1124...2009...3220....4901....7016....9737...13000...17025
.8..81..364..1007...2164...3997...6584...10219...14852...20847...28108...37095
.8.105..604..1823...4228...8051..13668...21609...31924...45309...61740...82067
.8.153.1018..3455...8440..16683..29012...47061...70374..101211..139098..186709
.8.217.1732..6495..16932..34695..62108..103013..156308..227701..316236..428111
.8.297.2956.12105..34068..72269.133716..226309..349160..515043..723892..987667
.8.393.5050.22459..68688.150677.288996..498569..783568.1170169.1665908.2290065
.8.585.8638.43255.139040.318575.627654.1111891.1772920.2686215.3862654.5366083

Examples

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

Crossrefs

Row 1 is A212133(n+1)

Formula

Empirical for column k:
k=1: a(n) = a(n-1)
k=2: a(n) = a(n-1) +4*a(n-4) -4*a(n-5)
k=3: a(n) = 2*a(n-1) -a(n-3) +a(n-4) -a(n-5) -a(n-6) +a(n-7)
k=4: [order 29] for n>30
k=5: [order 56]
k=6: [order 82] for n>84
Empirical for row n:
n=1: a(n) = 2*n^3 + 3*n^2 + 2*n + 1
n=2: a(n) = 2*a(n-1) +a(n-2) -4*a(n-3) +a(n-4) +2*a(n-5) -a(n-6); also a polynomial of degree 3 plus a linear quasipolynomial with period 2
n=3: [recurrence of order 12; also a polynomial of degree 3 plus a linear quasipolynomial with period 12]
n=4: [recurrence of order 24; also a polynomial of degree 3 plus a linear quasipolynomial with period 420]
n=5: [recurrence of order 48; also a polynomial of degree 3 plus a linear quasipolynomial with period 27720; note 2 12 420 27720 matches A060942]
n=6: [recurrence of order 92]