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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A079992 Number of permutations satisfying -k<=p(i)-i<=r and p(i)-i not in I, i=1..n, with k=3, r=3, I={-2,2}.

Original entry on oeis.org

1, 1, 2, 3, 9, 19, 49, 100, 233, 503, 1166, 2580, 5884, 13092, 29622, 66281, 149569, 335524, 755737, 1697149, 3819301, 8582469, 19306314, 43397191, 97600441, 219421360, 493425528, 1109386496, 2494606984, 5608933040, 12612101201
Offset: 0

Views

Author

Vladimir Baltic, Feb 17 2003

Keywords

References

  • D. H. Lehmer, Permutations with strongly restricted displacements. Combinatorial theory and its applications, II (Proc. Colloq., Balatonfured, 1969), pp. 755-770. North-Holland, Amsterdam, 1970.

Crossrefs

Formula

a(n) = a(n-1) +3*a(n-2) -a(n-3) +a(n-4) +a(n-5) +3*a(n-6) -5*a(n-7) -9*a(n-8) +a(n-9) +a(n-10) +a(n-11) -a(n-12) +a(n-13) +a(n-14).
G.f.: -(x^2-1)*(x^6+x^4+x^3+x^2-1)/(x^14 +x^13 -x^12 +x^11 +x^10 +x^9 -9*x^8 -5*x^7 +3*x^6 +x^5 +x^4 -x^3 +3*x^2 +x-1)

A079993 Number of permutations satisfying -k<=p(i)-i<=r and p(i)-i not in I, i=1..n, with k=3, r=3, I={0,2}.

Original entry on oeis.org

1, 0, 1, 1, 5, 9, 23, 39, 97, 197, 465, 969, 2161, 4605, 10202, 22051, 48438, 105028, 229692, 499620, 1091268, 2376641, 5185742, 11299467, 24645179, 53718931, 117144203, 255371099, 556824105, 1213941393, 2646824821, 5770590379
Offset: 0

Views

Author

Vladimir Baltic, Feb 17 2003

Keywords

Comments

Also, number of permutations satisfying -k<=p(i)-i<=r and p(i)-i not in I, i=1..n, with k=3, r=3, I={-2,0}.

References

  • D. H. Lehmer, Permutations with strongly restricted displacements. Combinatorial theory and its applications, II (Proc. Colloq., Balatonfured, 1969), pp. 755-770. North-Holland, Amsterdam, 1970.

Crossrefs

Formula

a(n) = 2*a(n-2) +2*a(n-3) +4*a(n-4) +6*a(n-5) +11*a(n-6) +a(n-7) -6*a(n-8) -4*a(n-9) -4*a(n-10) -8*a(n-11) -10*a(n-12) +a(n-13) +7*a(n-14) -2*a(n-16) +2*a(n-18) -a(n-20).
G.f.: -(x^3+1)*(x^11-x^9-2*x^8-x^7+2*x^6+x^4+2*x^3+x^2-1)/((x^18 -x^17 -2*x^16 +3*x^15 +x^14 -4*x^13 -4*x^12 +7*x^11 +7*x^10 -6*x^9 +3*x^8 +7*x^7 -4*x^6 -4*x^5 -3*x^4 +x^3 -2*x^2 -x+1) *(x^2+x+1)).

A079994 Number of permutations satisfying -k<=p(i)-i<=r and p(i)-i not in I, i=1..n, with k=3, r=3, I={0,1}.

Original entry on oeis.org

1, 0, 0, 1, 3, 9, 13, 25, 59, 147, 328, 690, 1478, 3285, 7357, 16249, 35561, 77974, 171891, 379401, 835954, 1839288, 4047688, 8914186, 19636159, 43244340, 95216488, 209653186, 461673635, 1016681969, 2238835524, 4929989552
Offset: 0

Views

Author

Vladimir Baltic, Feb 17 2003

Keywords

Comments

Also, number of permutations satisfying -k<=p(i)-i<=r and p(i)-i not in I, i=1..n, with k=3, r=3, I={-1,0}.

References

  • D. H. Lehmer, Permutations with strongly restricted displacements. Combinatorial theory and its applications, II (Proc. Colloq., Balatonfured, 1969), pp. 755-770. North-Holland, Amsterdam, 1970.

Crossrefs

Formula

a(n) = 2*a(n-2) +2*a(n-3) +4*a(n-4) +9*a(n-5) +10*a(n-6) -3*a(n-7) -9*a(n-8) -a(n-10) -12*a(n-11) -11*a(n-12) +a(n-13) +4*a(n-14) -a(n-15) +2*a(n-18) -a(n-20).
G.f.: -(x^14 -2*x^12 -x^11 -x^10 +2*x^9 -3*x^8 +5*x^6 +2*x^5 +x^4 +x^3 +2*x^2 -1)/ (x^20 -2*x^18 +x^15 -4*x^14 -x^13 +11*x^12 +12*x^11 +x^10 +9*x^8 +3*x^7 -10*x^6 -9*x^5 -4*x^4 -2*x^3 -2*x^2+1)

A079996 Number of permutations satisfying -k<=p(i)-i<=r and p(i)-i not in I, i=1..n, with k=3, r=3, I={1}.

Original entry on oeis.org

1, 1, 1, 3, 11, 33, 82, 198, 516, 1389, 3690, 9642, 25143, 65867, 173092, 454578, 1192227, 3125940, 8198836, 21509532, 56429115, 148023671, 388279519, 1018515853, 2671777153, 7008626377, 18384947908, 48227023198, 126508325008
Offset: 0

Views

Author

Vladimir Baltic, Feb 17 2003

Keywords

Comments

Also, number of permutations satisfying -k<=p(i)-i<=r and p(i)-i not in I, i=1..n, with k=3, r=3, I={-1}.

References

  • D. H. Lehmer, Permutations with strongly restricted displacements. Combinatorial theory and its applications, II (Proc. Colloq., Balatonfured, 1969), pp. 755-770. North-Holland, Amsterdam, 1970.

Crossrefs

Formula

a(n) = a(n-1) +2*a(n-2) +3*a(n-3) +4*a(n-4) +9*a(n-5) +9*a(n-6) -15*a(n-7) -12*a(n-8) +7*a(n-10) -6*a(n-11) -6*a(n-12) +5*a(n-13) +5*a(n-14) +3*a(n-15) -2*a(n-16) -a(n-17) +2*a(n-18) -a(n-19) -a(n-20).
G.f.: -(x^14 -2*x^12 +x^11 -x^10 -2*x^8 -2*x^7 +4*x^6 +x^4 +3*x^3 +2*x^2-1) /(x^20 +x^19 -2*x^18 +x^17 +2*x^16 -3*x^15 -5*x^14 -5*x^13 +6*x^12 +6*x^11 -7*x^10 +12*x^8 +15*x^7 -9*x^6 -9*x^5 -4*x^4 -3*x^3 -2*x^2 -x+1)

A079999 Number of permutations (p(1),p(2),...,p(n)) of (1,2,...,n) such that p(i)-i is in {-2,-1,3} for all i=1,...,n.

Original entry on oeis.org

1, 0, 0, 0, 1, 1, 1, 1, 1, 4, 4, 5, 7, 10, 16, 22, 29, 40, 60, 84, 118, 165, 230, 330, 466, 653, 919, 1297, 1831, 2585, 3640, 5124, 7233, 10201, 14380, 20272, 28572, 40289, 56816, 80096, 112912, 159196, 224449, 316456, 446164, 629004, 886821, 1250329, 1762801
Offset: 0

Views

Author

Vladimir Baltic, Feb 10 2003

Keywords

References

  • D. H. Lehmer, Permutations with strongly restricted displacements. Combinatorial theory and its applications, II (Proc. Colloq., Balatonfured, 1969), pp. 755-770. North-Holland, Amsterdam, 1970.

Crossrefs

Programs

  • Mathematica
    LinearRecurrence[{0,0,1,1,2,1,0,-1,0,-1},{1,0,0,0,1,1,1,1,1,4},50] (* Harvey P. Dale, Dec 12 2024 *)

Formula

Recurrence: a(n) = a(n-3) + a(n-4) + 2*a(n-5) + a(n-6) - a(n-8) - a(n-10) for n>=10.
G.f.: (1 - x^3 - x^5)/(1 - x^3 - x^4 - 2*x^5 - x^6 + x^8 + x^10).

A080001 Number of permutations satisfying -k<=p(i)-i<=r and p(i)-i not in I, i=1..n, with k=2, r=3, I={-1,0,2}.

Original entry on oeis.org

1, 0, 0, 1, 1, 1, 1, 2, 4, 3, 4, 8, 10, 13, 16, 24, 36, 43, 59, 85, 115, 156, 207, 289, 401, 533, 729, 1002, 1368, 1864, 2526, 3465, 4740, 6436, 8785, 11995, 16375, 22331, 30420, 41550, 56705, 77296, 105456, 143874, 196321, 267792, 365216, 498356
Offset: 0

Views

Author

Vladimir Baltic, Feb 10 2003

Keywords

References

  • D. H. Lehmer, Permutations with strongly restricted displacements. Combinatorial theory and its applications, II (Proc. Colloq., Balatonfured, 1969), pp. 755-770. North-Holland, Amsterdam, 1970.

Crossrefs

Formula

Recurrence: a(n) = a(n-3)+a(n-4)+2*a(n-5)-a(n-9)-a(n-10) G.f.: -(x^5-1)/(x^10+x^9-2*x^5-x^4-x^3+1)

A080002 Number of permutations satisfying -k<=p(i)-i<=r and p(i)-i not in I, i=1..n, with k=2, r=3, I={-1,0,1}.

Original entry on oeis.org

1, 0, 0, 0, 1, 1, 0, 0, 1, 3, 1, 1, 1, 6, 6, 4, 5, 10, 20, 16, 20, 25, 50, 60, 66, 85, 125, 190, 216, 281, 365, 545, 701, 883, 1156, 1576, 2176, 2761, 3636, 4784, 6560, 8620, 11265, 14856, 19840, 26600, 34825, 46045, 60856, 81420, 107625, 142055, 187881, 249461
Offset: 0

Views

Author

Vladimir Baltic, Feb 10 2003

Keywords

References

  • D. H. Lehmer, Permutations with strongly restricted displacements. Combinatorial theory and its applications, II (Proc. Colloq., Balatonfured, 1969), pp. 755-770. North-Holland, Amsterdam, 1970.

Crossrefs

Programs

  • Mathematica
    LinearRecurrence[{0,1,0,1,2,-1,-1,0,0,-1},{1,0,0,0,1,1,0,0,1,3},60] (* Harvey P. Dale, Dec 14 2011 *)

Formula

Recurrence: a(n) = a(n-2)+a(n-4)+2*a(n-5)-a(n-6)-a(n-7)-a(n-10).
G.f.: (1-x^2-x^5)/(x^10+x^7+x^6-2*x^5-x^4-x^2+1).

A080003 Number of permutations satisfying -k<=p(i)-i<=r and p(i)-i not in I, i=1..n, with k=2, r=3, I={1,2}.

Original entry on oeis.org

1, 1, 1, 1, 4, 8, 13, 22, 40, 77, 140, 252, 456, 834, 1525, 2775, 5049, 9195, 16760, 30536, 55617, 101304, 184544, 336193, 612424, 1115600, 2032216, 3702000, 6743761, 12284729, 22378393, 40765513, 74260396, 135276192, 246425309
Offset: 0

Views

Author

Vladimir Baltic, Feb 10 2003

Keywords

References

  • D. H. Lehmer, Permutations with strongly restricted displacements. Combinatorial theory and its applications, II (Proc. Colloq., Balatonfured, 1969), pp. 755-770. North-Holland, Amsterdam, 1970.

Crossrefs

Formula

Recurrence: a(n) = a(n-1)+a(n-3)+2*a(n-4)+2*a(n-5)+a(n-7)-a(n-8)-a(n-10).
G.f.: -(x^5+x^3-1)/(x^10+x^8-x^7-2*x^5-2*x^4-x^3-x+1)

A080004 Number of permutations satisfying -k<=p(i)-i<=r and p(i)-i not in I, i=1..n, with k=2, r=3, I={-1,2}.

Original entry on oeis.org

1, 1, 1, 2, 4, 9, 15, 25, 46, 84, 156, 280, 501, 909, 1647, 2990, 5408, 9773, 17695, 32033, 58000, 104976, 189968, 343860, 622409, 1126617, 2039201, 3690898, 6680644, 12092173, 21887215, 39616409, 71706406, 129790404, 234923948
Offset: 0

Views

Author

Vladimir Baltic, Feb 10 2003

Keywords

References

  • D. H. Lehmer, Permutations with strongly restricted displacements. Combinatorial theory and its applications, II (Proc. Colloq., Balatonfured, 1969), pp. 755-770. North-Holland, Amsterdam, 1970.

Crossrefs

Programs

  • Mathematica
    LinearRecurrence[{1,0,1,1,4,-1,1,0,-1,-1},{1,1,1,2,4,9,15,25,46,84},40] (* Harvey P. Dale, Jun 18 2013 *)

Formula

a(n) = a(n-1)+a(n-3)+a(n-4)+4*a(n-5)-a(n-6)+a(n-7)-a(n-9)-a(n-10).
G.f.: -(x^5-1)/(x^10+x^9-x^7+x^6-4*x^5-x^4-x^3-x+1).

A080005 Number of permutations satisfying -k<=p(i)-i<=r and p(i)-i not in I, i=1..n, with k=2, r=3, I={-1,1}.

Original entry on oeis.org

1, 1, 1, 2, 4, 7, 11, 19, 35, 62, 107, 186, 328, 578, 1012, 1771, 3107, 5455, 9568, 16774, 29417, 51603, 90513, 158741, 278404, 488301, 856448, 1502116, 2634532, 4620700, 8104269, 14214069, 24929981, 43724610, 76688540, 134503903, 235906039
Offset: 0

Views

Author

Vladimir Baltic, Feb 10 2003

Keywords

References

  • D. H. Lehmer, Permutations with strongly restricted displacements. Combinatorial theory and its applications, II (Proc. Colloq., Balatonfured, 1969), pp. 755-770. North-Holland, Amsterdam, 1970.

Crossrefs

Programs

  • Mathematica
    CoefficientList[Series[-(x^5 + x^2 - 1)/(x^10 - x^8 + 2*x^6 - x^5 - x^4 - x^2 - x + 1), {x, 0, 50}], x] (* Wesley Ivan Hurt, Jan 02 2017 *)

Formula

a(n) = a(n-1) + a(n-2) + a(n-4) + a(n-5) - 2*a(n-6) + a(n-8) - a(n-10), n>9.
G.f.: -(x^5+x^2-1)/(x^10-x^8+2*x^6-x^5-x^4-x^2-x+1).
Previous Showing 51-60 of 77 results. Next