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 1-6 of 6 results.

A053107 Expansion of 1/(1-8*x)^8.

Original entry on oeis.org

1, 64, 2304, 61440, 1351680, 25952256, 449839104, 7197425664, 107961384960, 1535450808320, 20882130993152, 273366078455808, 3462636993773568, 42617070692597760, 511404848311173120, 6000483553517764608, 69005560865454292992, 779356922715719073792
Offset: 0

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Author

Keywords

Comments

With a different offset, number of n-permutations (n>=7) of 9 objects: p, r, s, t, u, v, z, x, y with repetition allowed, containing exactly 7 u's. - Zerinvary Lajos, Feb 11 2010

Crossrefs

Programs

  • Magma
    [8^n* Binomial(n+7, 7): n in [0..20]]; // Vincenzo Librandi, Oct 16 2011
    
  • Mathematica
    Table[Binomial[n + 7, 7]*8^n, {n, 0, 20}] (* Zerinvary Lajos, Feb 11 2010 *)
    CoefficientList[Series[1/(1-8x)^8,{x,0,20}],x] (* or *) LinearRecurrence[ {64,-1792,28672,-286720,1835008,-7340032,16777216,-16777216},{1,64,2304,61440,1351680,25952256,449839104,7197425664},20] (* Harvey P. Dale, Jul 19 2018 *)
  • PARI
    vector(30, n, n--; 8^n*binomial(n+7,7)) \\ G. C. Greubel, Aug 16 2018
  • Sage
    [lucas_number2(n, 8, 0)*binomial(n,7)/8^7 for n in range(7, 22)] # Zerinvary Lajos, Mar 13 2009
    

Formula

a(n) = 8^n*binomial(n+7, 7).
G.f.: 1/(1-8*x)^8.

Extensions

More terms from Harvey P. Dale, Jul 19 2018

A173155 a(n) = binomial(n + 5, 5) * 8^n.

Original entry on oeis.org

1, 48, 1344, 28672, 516096, 8257536, 121110528, 1660944384, 21592276992, 268703891456, 3224446697472, 37520834297856, 425236122042368, 4710307813392384, 51140484831117312, 545498504865251328, 5727734301085138944, 59298896293587320832, 606166495445559279616
Offset: 0

Views

Author

Zerinvary Lajos, Feb 11 2010

Keywords

Comments

With a different offset, number of n-permutations (n>=5) of 9 objects: p, r, s, t, u, v, z, x, y with repetition allowed, containing exactly five (5) u's.

Crossrefs

Programs

  • Magma
    [8^n* Binomial(n+5, 5): n in [0..20]]; // Vincenzo Librandi, Oct 16 2011
  • Mathematica
    Table[Binomial[n + 5, 5]*8^n, {n, 0, 20}]

Formula

a(n) = C(n + 5, 5)*8^n, n>=0.
G.f.: 1/(1-8*x)^6. - Vincenzo Librandi, Oct 16 2011
From Amiram Eldar, Aug 29 2022: (Start)
Sum_{n>=0} 1/a(n) = 96040*log(8/7) - 38470/3.
Sum_{n>=0} (-1)^n/a(n) = 262440*log(9/8) - 30910. (End)

A140405 a(n) = binomial(n+6, 6)*5^n.

Original entry on oeis.org

1, 35, 700, 10500, 131250, 1443750, 14437500, 134062500, 1173046875, 9775390625, 78203125000, 604296875000, 4532226562500, 33120117187500, 236572265625000, 1656005859375000, 11385040283203125, 77016448974609375, 513442993164062500, 3377914428710937500
Offset: 0

Views

Author

Zerinvary Lajos, Jun 16 2008

Keywords

Comments

With a different offset, number of n-permutations (n>=6) of 6 objects: t, u, v, z, x, y with repetition allowed, containing exactly six (6) u's.
If n=6 then a(0)=1.
Example: a(1)=35 because we have
uuuuuut, uuuuutu, uuuutuu, uuutuuu, uutuuuu, utuuuuu, tuuuuuu,
uuuuuuv, uuuuuvu, uuuuvuu, uuuvuuu, uuvuuuu, uvuuuuu, vuuuuuu,
uuuuuuz, uuuuuzu, uuuuzuu, uuuzuuu, uuzuuuu, uzuuuuu, zuuuuuu,
uuuuuux, uuuuuxu, uuuuxuu, uuuxuuu, uuxuuuu, uxuuuuu, xuuuuuu,
uuuuuuy, uuuuuyu, uuuuyuu, uuuyuuu, uuyuuuu, uyuuuuu, yuuuuuu.

Crossrefs

Programs

  • Maple
    seq(binomial(n+6,6)*5^n,n=0..18);
  • Mathematica
    Table[Binomial[n+6,6]5^n,{n,0,20}] (* Harvey P. Dale, Dec 03 2017 *)

Formula

G.f.: 1/(1-5*x)^7. - Zerinvary Lajos, Aug 06 2008
From Amiram Eldar, Aug 29 2022: (Start)
Sum_{n>=0} 1/a(n) = 6856 - 30720*log(5/4).
Sum_{n>=0} (-1)^n/a(n) = 233280*log(6/5) - 42531. (End)

A172510 a(n) = binomial(n + 4, 4) * 8^n.

Original entry on oeis.org

1, 40, 960, 17920, 286720, 4128768, 55050240, 692060160, 8304721920, 95965675520, 1074815565824, 11725260718080, 125069447659520, 1308418837053440, 13458022323978240, 136374626216312832, 1363746262163128320, 13477021884906209280, 131775325096860712960
Offset: 0

Views

Author

Zerinvary Lajos, Feb 05 2010

Keywords

Crossrefs

Programs

  • Magma
    [Binomial(n + 4, 4)*8^n: n in [0..30]]; // Vincenzo Librandi, Jun 06 2011
    
  • Mathematica
    Table[Binomial[n + 4, 4]*8^n, {n, 0, 25}]
  • PARI
    Vec(1 / (1-8*x)^5 + O(x^30)) \\ Colin Barker, Jul 24 2017

Formula

G.f.: 1 / (1-8*x)^5. - R. J. Mathar, Feb 11 2010
a(n) = (8^(-1 + n)*(1 + n)*(2 + n)*(3 + n)*(4 + n)) / 3. - Colin Barker, Jul 24 2017
From Amiram Eldar, Aug 29 2022: (Start)
Sum_{n>=0} 1/a(n) = 4400/3 - 10976*log(8/7).
Sum_{n>=0} (-1)^n/a(n) = 23328*log(9/8) - 8240/3. (End)

A196280 a(n) = binomial(n+9, 9)*8^n.

Original entry on oeis.org

1, 80, 3520, 112640, 2928640, 65601536, 1312030720, 23991418880, 407854120960, 6525665935360, 99190122217472, 1442765414072320, 20198715797012480, 273459536944168960, 3594039628409077760, 46003707243636195328, 575046340545452441600, 7035861107850241638400
Offset: 0

Views

Author

Vincenzo Librandi, Oct 13 2011

Keywords

Crossrefs

Programs

  • Magma
    [Binomial(n+9, 9)*8^n: n in [0..20]];
  • Mathematica
    Table[Binomial[n+9,9]8^n,{n,0,20}] (* or *) LinearRecurrence[{80,-2880,61440,-860160,8257536,-55050240,251658240,-754974720,1342177280,-1073741824},{1,80,3520,112640,2928640,65601536,1312030720,23991418880,407854120960,6525665935360},20] (* Harvey P. Dale, May 13 2017 *)

Formula

a(n) = C(n+9,9)*8^n.
G.f.: 1 / (8*x-1)^10 . - R. J. Mathar, Oct 13 2011
From Amiram Eldar, Feb 17 2023: (Start)
Sum_{n>=0} 1/a(n) = 415065672*log(8/7) - 277121481/5.
Sum_{n>=0} (-1)^n/a(n) = 3099363912*log(9/8) - 12776837121/35. (End)

A197321 a(n) = binomial(n+10, 10)*8^n.

Original entry on oeis.org

1, 88, 4224, 146432, 4100096, 98402304, 2099249152, 40785412096, 734137417728, 12398765277184, 198380244434944, 3029807369551872, 44437174753427456, 628956934971588608, 8625695108181786624, 115009268109090488320, 1495120485418176348160, 18996824991195652423680
Offset: 0

Views

Author

Vincenzo Librandi, Oct 15 2011

Keywords

Crossrefs

Programs

  • Magma
    [8^n*Binomial(n+10, 10): n in [0..20]]
  • Mathematica
    Table[Binomial[n+10,10]8^n,{n,0,20}] (* Harvey P. Dale, Mar 05 2012 *)

Formula

a(n) = 8^n*C(n+10, 10).
G.f.: 1/(1-8*x)^11.
From Amiram Eldar, Feb 17 2023: (Start)
Sum_{n>=0} 1/a(n) = 3879700814/9 - 3228288560*log(8/7).
Sum_{n>=0} (-1)^n/a(n) = 30993639120*log(9/8) - 229983068738/63. (End)
Showing 1-6 of 6 results.