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.

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A202967 Number of arrays of 7 integers in -n..n with sum zero and adjacent elements differing in absolute value.

Original entry on oeis.org

6, 524, 9872, 66208, 289536, 941086, 2537024, 5933492, 12515772, 24295760, 44188086, 76110890, 125357152, 198686606, 304811136, 454458544, 660981870, 940393644, 1312104510, 1798910920, 2427885688, 3230300850, 4242680088
Offset: 1

Views

Author

R. H. Hardin Dec 26 2011

Keywords

Comments

Row 5 of A202962

Examples

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

Formula

Empirical: a(n) = 2*a(n-1) -a(n-2) +a(n-3) -2*a(n-5) +a(n-6) -3*a(n-7) +3*a(n-8) -a(n-9) +2*a(n-10) +a(n-11) -a(n-13) -2*a(n-14) +a(n-15) -3*a(n-16) +3*a(n-17) -a(n-18) +2*a(n-19) -a(n-21) +a(n-22) -2*a(n-23) +a(n-24)

A202968 Number of arrays of 8 integers in -n..n with sum zero and adjacent elements differing in absolute value.

Original entry on oeis.org

12, 1724, 47732, 447528, 2475008, 9824176, 31155004, 84017312, 200493156, 434793200, 873257136, 1646890444, 2946873064, 5043331924, 8307662160, 13238602092, 20492707704, 30919086656, 45598979576, 65890555856, 93479027928
Offset: 1

Views

Author

R. H. Hardin Dec 26 2011

Keywords

Comments

Row 6 of A202962

Examples

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

Formula

Empirical: a(n) = a(n-2) +3*a(n-3) +a(n-4) -a(n-5) -4*a(n-6) -4*a(n-7) -3*a(n-8) +a(n-9) +5*a(n-10) +6*a(n-11) +5*a(n-12) -2*a(n-14) -5*a(n-15) -4*a(n-16) -5*a(n-17) -2*a(n-18) +5*a(n-20) +6*a(n-21) +5*a(n-22) +a(n-23) -3*a(n-24) -4*a(n-25) -4*a(n-26) -a(n-27) +a(n-28) +3*a(n-29) +a(n-30) -a(n-32)

A202969 Number of arrays of 9 integers in -n..n with sum zero and adjacent elements differing in absolute value.

Original entry on oeis.org

6, 5908, 229714, 3020170, 21274708, 102972822, 384996502, 1196677486, 3233011170, 7831389294, 17375280238, 35875950626, 69754837982, 128899962066, 228011800792, 388342150524, 639825818930, 1023746518060, 1595913984468
Offset: 1

Views

Author

R. H. Hardin Dec 26 2011

Keywords

Comments

Row 7 of A202962

Examples

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

Formula

Empirical: a(n) = a(n-1) -a(n-2) +2*a(n-3) +2*a(n-5) -a(n-7) -a(n-8) -5*a(n-9) -a(n-10) -5*a(n-11) +4*a(n-12) -a(n-13) +9*a(n-14) +4*a(n-15) +7*a(n-16) +2*a(n-17) -2*a(n-18) -4*a(n-19) -11*a(n-20) -5*a(n-21) -11*a(n-22) +2*a(n-23) -2*a(n-24) +11*a(n-25) +5*a(n-26) +11*a(n-27) +4*a(n-28) +2*a(n-29) -2*a(n-30) -7*a(n-31) -4*a(n-32) -9*a(n-33) +a(n-34) -4*a(n-35) +5*a(n-36) +a(n-37) +5*a(n-38) +a(n-39) +a(n-40) -2*a(n-42) -2*a(n-44) +a(n-45) -a(n-46) +a(n-47)
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