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 1-8 of 8 results.

A247612 a(n) = Sum_{k=0..7} binomial(14,k)*binomial(n,k).

Original entry on oeis.org

1, 15, 120, 680, 3060, 11628, 38760, 116280, 316767, 788161, 1805100, 3840420, 7660250, 14446134, 25947612, 44668692, 74091645, 118941555, 185495056, 281936688, 418766304, 609260960, 869994720, 1221419808, 1688512539, 2301487461, 3096583140, 4116923020
Offset: 0

Views

Author

Vincenzo Librandi, Sep 22 2014

Keywords

Crossrefs

Programs

  • Magma
    [(1680+386012*n-958048*n^2+943761*n^3-455455*n^4+123123*n^5- 17017*n^6+1144*n^7)/1680: n in [0..40]];
    
  • Magma
    I:=[1,15,120,680,3060,11628,38760, 116280]; [n le 8 select I[n] else 8*Self(n-1)-28*Self(n-2)+56*Self(n-3)-70*Self(n-4)+56*Self(n-5) -28*Self(n-6)+8*Self(n-7)-Self(n-8): n in [1..40]];
    
  • Mathematica
    Table[(1680 + 386012 n - 958048 n^2 + 943761 n^3 - 455455 n^4 + 123123 n^5 - 17017 n^6 + 1144 n^7)/1680, {n, 0, 40}] (* or *) CoefficientList[Series[(1 + 7 x + 28 x^2 + 84 x^3 + 210 x^4 + 462 x^5 + 924 x^6 + 1716 x^7)/(1 - x)^8, {x, 0, 40}], x]
    LinearRecurrence[{8,-28,56,-70,56,-28,8,-1},{1,15,120,680,3060,11628,38760,116280},30] (* Harvey P. Dale, May 12 2017 *)
  • Sage
    m=7; [sum((binomial(2*m,k)*binomial(n,k)) for k in (0..m)) for n in (0..40)] # Bruno Berselli, Sep 22 2014

Formula

G.f.: (1 + 7*x + 28*x^2 + 84*x^3 + 210*x^4 + 462*x^5 + 924*x^6 + 1716*x^7) / (1-x)^8.
a(n) = 8*a(n-1) - 28*a(n-2) + 56*a(n-3) - 70*a(n-4) + 56*a(n-5) - 28*a(n-6) + 8*a(n-7) - a(n-8).
a(n) = (1680 + 386012*n - 958048*n^2 + 943761*n^3 - 455455*n^4 + 123123*n^5 - 17017*n^6 + 1144*n^7)/1680.

Extensions

Definition edited by Robert Israel, Sep 22 2014

A247609 a(n) = Sum_{k=0..4} binomial(8,k)*binomial(n,k).

Original entry on oeis.org

1, 9, 45, 165, 495, 1231, 2639, 5055, 8885, 14605, 22761, 33969, 48915, 68355, 93115, 124091, 162249, 208625, 264325, 330525, 408471, 499479, 604935, 726295, 865085, 1022901, 1201409, 1402345, 1627515, 1878795, 2158131, 2467539, 2809105, 3184985, 3597405
Offset: 0

Views

Author

Vincenzo Librandi, Sep 22 2014

Keywords

Crossrefs

Programs

  • Magma
    [(12-58*n+217*n^2-98*n^3+35*n^4)/12: n in [0..40]];
    
  • Magma
    [1+8*Binomial(n, 1)+28*Binomial(n, 2)+56*Binomial(n, 3)+70*Binomial(n,4): n in [0..40]];
    
  • Magma
    I:=[1,9,45,165,495]; [n le 5 select I[n] else 5*Self(n-1)-10*Self(n-2)+10*Self(n-3)-5*Self(n-4)+Self(n-5): n in [1..40]];
    
  • Mathematica
    Table[(12 - 58 n + 217 n^2 - 98 n^3 + 35 n^4)/12, {n, 0, 50}] (* or *) CoefficientList[Series[(1 + 4 x + 10 x^2 + 20 x^3 + 35 x^4)/(1 - x)^5, {x, 0, 50}], x]
    LinearRecurrence[{5,-10,10,-5,1},{1,9,45,165,495},40] (* Harvey P. Dale, Oct 19 2024 *)
  • Sage
    m=4; [sum((binomial(2*m,k)*binomial(n,k)) for k in (0..m)) for n in (0..40)] # Bruno Berselli, Sep 22 2014

Formula

G.f.: (1 + 4*x + 10*x^2 + 20*x^3 + 35*x^4)/(1 - x)^5.
a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5).
a(n) = (12 - 58*n + 217*n^2 - 98*n^3 + 35*n^4)/12.
a(n) = 1 + 8*Binomial(n, 1) + 28*Binomial(n, 2) + 56*Binomial(n, 3) + 70*Binomial(n, 4).

A247611 a(n) = Sum_{k=0..6} binomial(12,k)*binomial(n,k).

Original entry on oeis.org

1, 13, 91, 455, 1820, 6188, 18564, 49596, 119139, 260743, 527065, 996205, 1778966, 3027038, 4942106, 7785882, 11891061, 17673201, 25643527, 36422659, 50755264, 69525632, 93774176, 124714856, 163753527, 212507211, 272824293, 346805641, 436826650
Offset: 0

Views

Author

Vincenzo Librandi, Sep 22 2014

Keywords

Crossrefs

Programs

  • Magma
    [(120-8042*n+20581*n^2-17380*n^3+7645*n^4-1518*n^5+ 154*n^6)/120: n in [0..40]];
    
  • Magma
    I:=[1,13,91,455,1820,6188,18564]; [n le 7 select I[n] else 7*Self(n-1)-21*Self(n-2)+35*Self(n-3)-35*Self(n-4)+21*Self(n-5)-7*Self(n-6)+Self(n-7): n in [1..40]];
    
  • Mathematica
    Table[(120 - 8042 n + 20581 n^2 - 17380 n^3 + 7645 n^4 - 1518 n^5 + 154 n^6)/120, {n, 0, 40}] (* or *) CoefficientList[Series[(1 + 6 x + 21 x^2 + 56 x^3 + 126 x^4 + 252 x^5 + 462 x^6)/(1 - x)^7, {x, 0, 40}], x]
  • Sage
    m=6; [sum((binomial(2*m,k)*binomial(n,k)) for k in (0..m)) for n in (0..40)] # Bruno Berselli, Sep 22 2014

Formula

G.f.: (1 + 6*x + 21*x^2 + 56*x^3 + 126*x^4 + 252*x^5 + 462*x^6) / (1-x)^7.
a(n) = 7*a(n-1) - 21*a(n-2) + 35*a(n-3) - 35*a(n-4) + 21*a(n-5) - 7*a(n-6) + a(n-7).
a(n) = (120 - 8042*n + 20581*n^2 - 17380*n^3 + 7645*n^4 -1518*n^5 + 154*n^6)/120.

A247610 a(n) = Sum_{k=0..5} binomial(10,k)*binomial(n,k).

Original entry on oeis.org

1, 11, 66, 286, 1001, 3003, 7798, 17858, 36873, 70003, 124130, 208110, 333025, 512435, 762630, 1102882, 1555697, 2147067, 2906722, 3868382, 5070009, 6554059, 8367734, 10563234, 13198009, 16335011, 20042946, 24396526, 29476721, 35371011, 42173638, 49985858
Offset: 0

Views

Author

Vincenzo Librandi, Sep 22 2014

Keywords

Crossrefs

Programs

  • Magma
    [(20+508*n-925*n^2+820*n^3-245*n^4+42*n^5)/20: n in [0..40]];
    
  • Magma
    I:=[1,11,66,286,1001,3003]; [n le 6 select I[n] else 6*Self(n-1)-15*Self(n-2)+20*Self(n-3)-15*Self(n-4)+6*Self(n-5)-Self(n-6): n in [1..40]];
    
  • Mathematica
    Table[(20 + 508 n - 925 n^2 + 820 n^3 - 245 n^4 + 42 n^5)/20, {n, 0, 40}] (* or *) CoefficientList[Series[(1 + 5 x + 15 x^2 + 35 x^3 + 70 x^4 + 126 x^5)/(1 - x)^6, {x, 0, 40}], x]
    LinearRecurrence[{6,-15,20,-15,6,-1},{1,11,66,286,1001,3003},40] (* Harvey P. Dale, Apr 20 2022 *)
  • Sage
    m=5; [sum((binomial(2*m,k)*binomial(n,k)) for k in (0..m)) for n in (0..40)] # Bruno Berselli, Sep 22 2014

Formula

G.f.: (1 + 5*x + 15*x^2 + 35*x^3 + 70*x^4 + 126*x^5) / (1-x)^6.
a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 6*a(n-5) - a(n-6).
a(n) = (20 + 508*n - 925*n^2 + 820*n^3 - 245*n^4 + 42*n^5)/20.

A374452 Iterated rascal triangle R3: T(n,k) = Sum_{m=0..3} binomial(n-k,m)*binomial(k,m).

Original entry on oeis.org

1, 1, 1, 1, 2, 1, 1, 3, 3, 1, 1, 4, 6, 4, 1, 1, 5, 10, 10, 5, 1, 1, 6, 15, 20, 15, 6, 1, 1, 7, 21, 35, 35, 21, 7, 1, 1, 8, 28, 56, 69, 56, 28, 8, 1, 1, 9, 36, 84, 121, 121, 84, 36, 9, 1, 1, 10, 45, 120, 195, 226, 195, 120, 45, 10, 1
Offset: 0

Views

Author

Kolosov Petro, Jul 08 2024

Keywords

Comments

Triangle T(n,k) is the third triangle R3 among the rascal-family triangles; A077028 is triangle R1, A374378 is triangle R2.
Triangle T(n,k) equals Pascal's triangle A007318 through row 2i+1, i=2 (i.e., row 7).
Triangle T(n,k) equals Pascal's triangle A007318 through column i, i=2 (i.e., column 3).

Examples

			Triangle begins:
--------------------------------------------------
k=     0   1   2   3    4    5    6   7   8   9 10
--------------------------------------------------
n=0:   1
n=1:   1   1
n=2:   1   2   1
n=3:   1   3   3   1
n=4:   1   4   6   4    1
n=5:   1   5  10  10    5    1
n=6:   1   6  15  20   15    6    1
n=7:   1   7  21  35   35   21    7   1
n=8:   1   8  28  56   69   56   28   8   1
n=9:   1   9  36  84  121  121   84  36   9   1
n=10:  1  10  45 120  195  226  195  120  45  10  1
		

Crossrefs

Programs

  • Mathematica
    t[n_, k_] := Sum[Binomial[n - k, m]*Binomial[k, m], {m, 0, 3}]; Column[Table[t[n, k], {n, 0, 12}, {k, 0, n}], Left]

Formula

T(n,k) = 1 + k*(n-k) + 1/4*(k-1)*k*(n-k-1)*(n-k) + 1/36*(k-2)*(k-1)*k*(n-k-2)*(n-k-1)*(n-k).
Row sums give A008860(n).
Diagonal T(n+1, n) gives A000027(n).
Diagonal T(n+2, n) gives A000217(n).
Diagonal T(n+3, n) gives A000292(n).
Diagonal T(n+4, n) gives A005894(n).
Diagonal T(n+6, n) gives A247608(n).
Column k=4 difference binomial(n+8, 4) - T(n+8, 4) gives C(n+4,4)=A007318(n+4,4).
Column k=5 difference binomial(n+9, 5) - T(n+9, 5) gives sixth column of (1,5)-Pascal triangle A096943.
G.f.: (1 + 4*x^6*y^3 - 3*x*(1 + y) - 6*x^5*y^2*(1 + y) + 2*x^4*y*(2 + 7*y+ 2*y^2) + x^2*(3 + 10*y + 3*y^2) - x^3*(1 + 11*y + 11*y^2 + y^3))/((1 - x)^4*(1 - x*y)^4). - Stefano Spezia, Jul 09 2024

A247613 a(n) = Sum_{k=0..8} binomial(16,k)*binomial(n,k).

Original entry on oeis.org

1, 17, 153, 969, 4845, 20349, 74613, 245157, 735471, 2031535, 5189327, 12316239, 27322191, 57029103, 112740255, 212383935, 383358645, 666220005, 1119362365, 1824861005, 2895653673, 4484253081, 6793194849, 10087438257, 14708950035, 21093714291
Offset: 0

Views

Author

Vincenzo Librandi, Sep 23 2014

Keywords

Crossrefs

Programs

  • Magma
    m:=8; [&+[Binomial(2*m,k)*Binomial(n,k): k in [0..m]]: n in [0..40]];
    
  • Magma
    [(20160-15076944*n+40499716*n^2-42247940*n^3 +23174515*n^4-7234136*n^5+1335334*n^6-134420*n^7 +6435*n^8)/20160: n in [0..40]];
    
  • Mathematica
    Table[(20160 - 15076944 n + 40499716 n^2 - 42247940 n^3 + 23174515 n^4 - 7234136 n^5 + 1335334 n^6 - 134420 n^7 + 6435 n^8)/20160, {n, 0, 40}] (* or *) CoefficientList[Series[(1 + 8 x + 36 x^2 + 120 x^3 + 330 x^4 + 792 x^5 + 1716 x^6 + 3432 x^7 + 6435 x^8)/(1 - x)^9, {x, 0, 40}], x]
    Table[Sum[Binomial[16,k]Binomial[n,k],{k,0,8}],{n,0,30}] (* or *) LinearRecurrence[{9,-36,84,-126,126,-84,36,-9,1},{1,17,153,969,4845,20349,74613,245157,735471},40] (* Harvey P. Dale, Mar 25 2015 *)
  • Sage
    m=8; [sum((binomial(2*m,k)*binomial(n,k)) for k in (0..m)) for n in (0..40)] # Bruno Berselli, Sep 23 2014

Formula

G.f.: (1 + 8*x + 36*x^2 + 120*x^3 + 330*x^4 + 792*x^5 + 1716*x^6 + 3432*x^7 + 6435*x^8) / (1-x)^9.
a(n) = 9*a(n-1) - 36*a(n-2) + 84*a(n-3) - 126*a(n-4) + 126*a(n-5) - 84*a(n-6) + 36*a(n-7) - 9*a(n-8) + a(n-9).
a(n) = (20160 - 15076944*n + 40499716*n^2 - 42247940*n^3 + 23174515*n^4 - 7234136*n^5 + 1335334*n^6 - 134420*n^7 + 6435*n^8) / 20160.

A247614 a(n) = Sum_{k=0..9} binomial(18,k)*binomial(n,k).

Original entry on oeis.org

1, 19, 190, 1330, 7315, 33649, 134596, 480700, 1562275, 4686825, 13079352, 34084128, 83204745, 191006115, 414237570, 852920310, 1675575165, 3155247975, 5719519850, 10018268150, 17013571223, 28096825757, 45238870040, 71179679480, 109665022415
Offset: 0

Views

Author

Vincenzo Librandi, Sep 23 2014

Keywords

Crossrefs

Programs

  • Magma
    m:=9; [&+[Binomial(2*m,k)*Binomial(n,k): k in [0..m]]: n in [0..40]];
    
  • Magma
    [(181440+462101904*n-1283316876*n^2+1433031524*n^3 -853620201*n^4+303063726*n^5-66245634*n^6 +8905416*n^7-678249*n^8+24310*n^9)/181440: n in [0..40]];
    
  • Mathematica
    Table[(181440 + 462101904 n - 1283316876 n^2 + 1433031524 n^3 - 853620201 n^4 + 303063726 n^5 - 66245634 n^6 + 8905416 n^7 - 678249 n^8 + 24310 n^9)/181440, {n, 0, 40}] (* or *) CoefficientList[Series[(1 + 9 x + 45 x^2 + 165 x^3 + 495 x^4 + 1287 x^5 + 3003 x^6 + 6435 x^7 + 12870 x^8 + 24310 x^9)/(1 - x)^10, {x, 0, 40}], x]
    LinearRecurrence[{10,-45,120,-210,252,-210,120,-45,10,-1},{1,19,190,1330,7315,33649,134596,480700,1562275,4686825},30] (* Harvey P. Dale, Jul 19 2019 *)
  • Sage
    m=9; [sum((binomial(2*m,k)*binomial(n,k)) for k in (0..m)) for n in (0..40)] # Bruno Berselli, Sep 23 2014

Formula

G.f.: (1 +9*x +45*x^2 +165*x^3 +495*x^4 +1287*x^5 +3003*x^6 + 6435*x^7 +12870*x^8 +24310*x^9) / (1-x)^10.
a(n) = 10*a(n-1) -45*a(n-2) +120*a(n-3) -210*a(n-4) +252*a(n-5) -210*a(n-6) +120*a(n-7) -45*a(n-8) +10*a(n-9) -a(n-10).
a(n) = (181440 + 462101904*n - 1283316876*n^2 + 1433031524*n^3 - 853620201*n^4 + 303063726*n^5 - 66245634*n^6+8905416*n^7 - 678249*n^8 + 24310*n^9) / 181440.

A247615 a(n) = Sum_{k=0..10} binomial(20,k)*binomial(n,k).

Original entry on oeis.org

1, 21, 231, 1771, 10626, 53130, 230230, 888030, 3108105, 10015005, 30045015, 84504355, 223651350, 558350430, 1318250890, 2952624906, 6296642121, 12834146941, 25098124271, 47262174531, 85990654178, 151631858378, 259857912678, 433877085278, 707369215553
Offset: 0

Views

Author

Vincenzo Librandi, Sep 23 2014

Keywords

Crossrefs

Programs

  • Magma
    m:=10; [&+[Binomial(2*m,k)*Binomial(n,k): k in [0..m]]: n in [0..40]];
    
  • Magma
    I:=[1, 21, 231, 1771, 10626, 53130, 230230, 888030, 3108105, 10015005, 30045015]; [n le 11 select I[n] else 11*Self(n-1) -55*Self(n-2) +165*Self(n-3) -330*Self(n-4) +462*Self(n-5) -462*Self(n-6) +330*Self(n-7) -165*Self(n-8) +55*Self(n-9) -11*Self(n-10) +Self(n-11): n in [1..40]];
    
  • Mathematica
    CoefficientList[Series[(1 + 10 x + 55 x^2 + 220 x^3 + 715 x^4 + 2002 x^5 + 5005 x^6 + 11440 x^7 + 24310 x^8 + 48620 x^9 + 92378 x^10)/(1 - x)^11, {x, 0, 40}], x]
    Table[Sum[Binomial[20,k]Binomial[n,k],{k,0,10}],{n,0,30}] (* or *) LinearRecurrence[{11,-55,165,-330,462,-462,330,-165,55,-11,1},{1,21,231,1771,10626,53130,230230,888030,3108105,10015005,30045015},30] (* Harvey P. Dale, May 19 2015 *)
  • Sage
    m=10; [sum((binomial(2*m,k)*binomial(n,k)) for k in (0..m)) for n in (0..40)] # Bruno Berselli, Sep 23 2014

Formula

G.f.: (1 + 10*x + 55*x^2 + 220*x^3 + 715*x^4 + 2002*x^5 + 5005*x^6 + 11440*x^7 + 24310*x^8 + 48620*x^9 + 92378*x^10) / (1-x)^11.
a(n) = 11*a(n-1) -55*a(n-2) +165*a(n-3) -330*a(n-4) +462*a(n-5) -462*a(n-6)+330*a(n-7) -165*a(n-8) +55*a(n-9) -11*a(n-10) +a(n-11).
a(n) = 1 - 5512999*n/630 + 212329883*n^2/8400 - 134689309*n^3/4536 + 3453077689*n^4/181440 - 64212077*n^5/8640 + 80300707*n^6/43200 - 1817521*n^7/6048 + 1860157*n^8/60480 - 331721*n^9/181440 + 46189*n^10/907200.
Showing 1-8 of 8 results.