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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A010967 a(n) = binomial coefficient C(n,14).

Original entry on oeis.org

1, 15, 120, 680, 3060, 11628, 38760, 116280, 319770, 817190, 1961256, 4457400, 9657700, 20058300, 40116600, 77558760, 145422675, 265182525, 471435600, 818809200, 1391975640, 2319959400, 3796297200, 6107086800, 9669554100, 15084504396, 23206929840, 35240152720
Offset: 14

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Author

Keywords

Comments

In this sequence there are no primes. - Artur Jasinski, Dec 02 2007

Crossrefs

Programs

Formula

a(n) = A110555(n+1,14). - Reinhard Zumkeller, Jul 27 2005
a(n+13) = n(n+1)(n+2)(n+3)(n+4)(n+5)(n+6)(n+7)(n+8)(n+9)(n+10)(n+11)(n+12)(n+13)/14!. - Artur Jasinski, Dec 02 2007, R. J. Mathar, Jul 07 2009
G.f.: x^14/(1-x)^15. - Zerinvary Lajos, Aug 06 2008, R. J. Mathar, Jul 07 2009
a(n) = n/(n-14) * a(n-1), n > 14. - Vincenzo Librandi, Mar 26 2011
From Amiram Eldar, Dec 10 2020: (Start)
Sum_{n>=14} 1/a(n) = 14/13.
Sum_{n>=14} (-1)^n/a(n) = A001787(14)*log(2) - A242091(14)/13! = 114688*log(2) - 102309709/1287 = 0.9404563356... (End)

Extensions

Some formulas rewritten for the correct offset by R. J. Mathar, Jul 07 2009

A010972 a(n) = binomial(n,19).

Original entry on oeis.org

1, 20, 210, 1540, 8855, 42504, 177100, 657800, 2220075, 6906900, 20030010, 54627300, 141120525, 347373600, 818809200, 1855967520, 4059928950, 8597496600, 17672631900, 35345263800, 68923264410, 131282408400, 244662670200, 446775310800, 800472431850
Offset: 19

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Author

Keywords

Comments

In this sequence there are no primes. - Artur Jasinski, Dec 02 2007

Crossrefs

Programs

Formula

a(n+18) = n*(n+1)*(n+2)*(n+3)*(n+4)*(n+5)*(n+6)*(n+7)*(n+8)*(n+9)*(n+10)*(n+11)*(n+12)*(n+13)*(n+14)*(n+15)*(n+16)*(n+17)*(n+18)/19!. - Artur Jasinski, Dec 02 2007; R. J. Mathar, Jul 07 2009
G.f.: x^19/(1-x)^20. - Zerinvary Lajos, Aug 04 2008; R. J. Mathar, Jul 07 2009
a(n) = n/(n-19) * a(n-1), n > 19. - Vincenzo Librandi, Mar 26 2011
From Amiram Eldar, Dec 11 2020: (Start)
Sum_{n>=19} 1/a(n) = 19/18.
Sum_{n>=19} (-1)^(n+1)/a(n) = A001787(19)*log(2) - A242091(19)/18! = 4980736*log(2) - 10574853703013/3063060 = 0.9542064261... (End)

A010968 a(n) = binomial(n,15).

Original entry on oeis.org

1, 16, 136, 816, 3876, 15504, 54264, 170544, 490314, 1307504, 3268760, 7726160, 17383860, 37442160, 77558760, 155117520, 300540195, 565722720, 1037158320, 1855967520, 3247943160, 5567902560, 9364199760, 15471286560, 25140840660, 40225345056, 63432274896
Offset: 15

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Author

Keywords

Comments

There are no primes in this sequence. - Artur Jasinski, Dec 02 2007

Crossrefs

Programs

Formula

a(n) = -A110555(n+1,15). - Reinhard Zumkeller, Jul 27 2005
a(n+14) = n(n+1)(n+2)(n+3)(n+4)(n+5)(n+6)(n+7)(n+8)(n+9)(n+10)(n+11)(n+12)(n+13)(n+14)/15!. - Artur Jasinski, Dec 02 2007; R. J. Mathar, Jul 07 2009
G.f.: x^15/(1-x)^16. - Zerinvary Lajos, Aug 06 2008; R. J. Mathar, Jul 07 2009
a(n) = n/(n-15) * a(n-1), n > 15. - Vincenzo Librandi, Mar 26 2011
From Amiram Eldar, Dec 10 2020: (Start)
Sum_{n>=15} 1/a(n) = 15/14.
Sum_{n>=15} (-1)^(n+1)/a(n) = A001787(15)*log(2) - A242091(15)/14! = 245760*log(2) - 1023103525/6006 = 0.9438350048... (End)

Extensions

Some formulas adjusted to the offset by R. J. Mathar, Jul 07 2009

A010970 a(n) = binomial(n,17).

Original entry on oeis.org

1, 18, 171, 1140, 5985, 26334, 100947, 346104, 1081575, 3124550, 8436285, 21474180, 51895935, 119759850, 265182525, 565722720, 1166803110, 2333606220, 4537567650, 8597496600, 15905368710, 28781143380, 51021117810, 88732378800, 151584480450, 254661927156
Offset: 17

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Author

Keywords

Comments

In this sequence there are no primes. - Artur Jasinski, Dec 02 2007

Crossrefs

Programs

Formula

a(n+16) = n*(n+1)*(n+2)*(n+3)*(n+4)*(n+5)*(n+6)*(n+7)*(n+8)*(n+9)*(n+10)*(n+11)*(n+12)*(n+13)*(n+14)*(n+15)*(n+16)/17!. - Artur Jasinski, Dec 02 2007; R. J. Mathar, Jul 07 2009
G.f.: x^17/(1-x)^18. - Zerinvary Lajos, Aug 06 2008; R. J. Mathar, Jul 07 2009
a(n) = n/(n-17) * a(n-1), n > 17. - Vincenzo Librandi, Mar 26 2011
From Amiram Eldar, Dec 10 2020: (Start)
Sum_{n>=17} 1/a(n) = 17/16.
Sum_{n>=17} (-1)^(n+1)/a(n) = A001787(17)*log(2) - A242091(17)/16! = 1114112*log(2) - 556570716997/720720 = 0.9495520222... (End)

A010971 a(n) = binomial(n,18).

Original entry on oeis.org

1, 19, 190, 1330, 7315, 33649, 134596, 480700, 1562275, 4686825, 13123110, 34597290, 86493225, 206253075, 471435600, 1037158320, 2203961430, 4537567650, 9075135300, 17672631900, 33578000610, 62359143990, 113380261800, 202112640600, 353697121050, 608359048206
Offset: 18

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Comments

Coordination sequence for 18-dimensional cyclotomic lattice Z[zeta_19].
Product of 18 consecutive numbers divided by 18!. - Artur Jasinski, Dec 02 2007
In this sequence only 19 is prime. - Artur Jasinski, Dec 02 2007
With a different offset, number of n-permutations (n>=18) of 2 objects: u,v, with repetition allowed, containing exactly (18) u's. - Zerinvary Lajos, Aug 04 2008

Crossrefs

Programs

  • Magma
    [Binomial(n, 18): n in [18..50]]; // Vincenzo Librandi, Aug 08 2017
    
  • Maple
    seq(binomial(n,18),n=18..38); # Zerinvary Lajos, Aug 04 2008
  • Mathematica
    Table[n(n+1)(n+2)(n+3)(n+4)(n+5)(n+6)(n+7)(n+8)(n+9)(n+10)(n+11)(n+12)(n+13)(n+14)(n+15)(n+16)(n+17)/18!,{n,1,100}] (* Artur Jasinski, Dec 02 2007 *)
    Table[Binomial[n, 18], {n, 18, 50}] (* Vincenzo Librandi, Aug 08 2017 *)
  • PARI
    for(n=18,50, print1(binomial(n,18), ", ")) \\ G. C. Greubel, Nov 23 2017

Formula

a(n+17) = n*(n+1)*(n+2)*(n+3)*(n+4)*(n+5)*(n+6)*(n+7)*(n+8)*(n+9)*(n+10)*(n+11)*(n+12)*(n+13)*(n+14)*(n+15)*(n+16)*(n+17)/18!. - Artur Jasinski, Dec 02 2007; R. J. Mathar, Jul 07 2009
G.f.: x^18/(1-x)^19. - Zerinvary Lajos, Aug 04 2008; R. J. Mathar, Jul 07 2009
From Amiram Eldar, Dec 10 2020: (Start)
Sum_{n>=18} 1/a(n) = 18/17.
Sum_{n>=18} (-1)^n/a(n) = A001787(18)*log(2) - A242091(18)/17! = 2359296*log(2) - 556571077357/340340 = 0.9519925176... (End)

Extensions

Some formulas adjusted to the offset by R. J. Mathar, Jul 07 2009

A010980 a(n) = binomial(n,27).

Original entry on oeis.org

1, 28, 406, 4060, 31465, 201376, 1107568, 5379616, 23535820, 94143280, 348330136, 1203322288, 3910797436, 12033222880, 35240152720, 98672427616, 265182149218, 686353797976, 1715884494940, 4154246671960, 9762479679106, 22314239266528, 49699896548176
Offset: 27

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Crossrefs

Programs

Formula

From Zerinvary Lajos, Aug 18 2008: (Start)
a(n) = C(n,27), n >= 27.
G.f.: x^27/(1-x)^28. (End)
From Amiram Eldar, Dec 11 2020: (Start)
Sum_{n>=27} 1/a(n) = 27/26.
Sum_{n>=27} (-1)^(n+1)/a(n) = A001787(27)*log(2) - A242091(27)/26! = 1811939328*log(2) - 233492834118075846/185910725 = 0.9665300296... (End)

A010984 Binomial coefficient C(n,31).

Original entry on oeis.org

1, 32, 528, 5984, 52360, 376992, 2324784, 12620256, 61523748, 273438880, 1121099408, 4280561376, 15338678264, 51915526432, 166871334960, 511738760544, 1503232609098, 4244421484512, 11554258485616, 30405943383200, 77535155627160, 191991813933920
Offset: 31

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Crossrefs

Programs

Formula

G.f.: x^31/(1-x)^32. - Zerinvary Lajos, Dec 19 2008; adapted to offset by Enxhell Luzhnica, Jan 21 2017
From Amiram Eldar, Dec 12 2020: (Start)
Sum_{n>=31} 1/a(n) = 31/30.
Sum_{n>=31} (-1)^(n+1)/a(n) = A001787(31)*log(2) - A242091(31)/30! = 33285996544*log(2) - 6717121856795533085173/291136195350 = 0.9704936372... (End)

A010985 Binomial coefficient C(n,32).

Original entry on oeis.org

1, 33, 561, 6545, 58905, 435897, 2760681, 15380937, 76904685, 350343565, 1471442973, 5752004349, 21090682613, 73006209045, 239877544005, 751616304549, 2254848913647, 6499270398159, 18053528883775, 48459472266975, 125994627894135, 317986441828055
Offset: 32

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Crossrefs

Programs

Formula

G.f.: x^32/(1-x)^33. - Zerinvary Lajos, Dec 19 2008; adapted to offset by Enxhell Luzhnica, Jan 21 2017
From Amiram Eldar, Dec 12 2020: (Start)
Sum_{n>=32} 1/a(n) = 32/31.
Sum_{n>=32} (-1)^n/a(n) = A001787(32)*log(2) - A242091(32)/31! = 68719476736*log(2) - 214947899422115237851136/4512611027925 = 0.9713417027... (End)

A010986 Binomial coefficient C(n,33).

Original entry on oeis.org

1, 34, 595, 7140, 66045, 501942, 3262623, 18643560, 95548245, 445891810, 1917334783, 7669339132, 28760021745, 101766230790, 341643774795, 1093260079344, 3348108992991, 9847379391150, 27900908274925, 76360380541900, 202355008436035, 520341450264090
Offset: 33

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Crossrefs

Programs

Formula

G.f.: x^33/(1-x)^34. - Zerinvary Lajos, Dec 19 2008; adapted to offset by Enxhell Luzhnica, Jan 23 2017
From Amiram Eldar, Dec 12 2020: (Start)
Sum_{n>=33} 1/a(n) = 33/32.
Sum_{n>=33} (-1)^(n+1)/a(n) = A001787(33)*log(2) - A242091(33)/32! = 141733920768*log(2) - 429895798848743086730197/4375865239200 = 0.9721422619... (End)

A010987 Binomial coefficient C(n,34).

Original entry on oeis.org

1, 35, 630, 7770, 73815, 575757, 3838380, 22481940, 118030185, 563921995, 2481256778, 10150595910, 38910617655, 140676848445, 482320623240, 1575580702584, 4923689695575, 14771069086725, 42671977361650, 119032357903550, 321387366339585, 841728816603675
Offset: 34

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Crossrefs

Programs

Formula

G.f.: x^34/(1-x)^35 . - Zerinvary Lajos, Dec 19 2008; adapted to offset by Enxhell Luzhnica, Jan 23 2017
From Amiram Eldar, Dec 12 2020: (Start)
Sum_{n>=34} 1/a(n) = 34/33.
Sum_{n>=34} (-1)^n/a(n) = A001787(34)*log(2) - A242091(34)/33! = 292057776128*log(2) - 429895798850931019349797/2123581660200 = 0.9728992064... (End)
Previous Showing 11-20 of 94 results. Next