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.

A016953 a(n) = (6*n + 3)^9.

Original entry on oeis.org

19683, 387420489, 38443359375, 794280046581, 7625597484987, 46411484401953, 208728361158759, 756680642578125, 2334165173090451, 6351461955384057, 15633814156853823, 35452087835576229, 75084686279296875, 150094635296999121, 285544154243029527, 520411082988487293
Offset: 0

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Formula

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). - Harvey P. Dale, Jan 19 2012
From Amiram Eldar, Mar 30 2022: (Start)
a(n) = A016945(n)^9 = A016947(n)^3.
a(n) = 3^9*A016761(n).
Sum_{n>=0} 1/a(n) = 511*zeta(9)/10077696.
Sum_{n>=0} (-1)^n/a(n) = 277*Pi^9/162533081088. (End)

A016749 a(n) = (2*n)^9.

Original entry on oeis.org

0, 512, 262144, 10077696, 134217728, 1000000000, 5159780352, 20661046784, 68719476736, 198359290368, 512000000000, 1207269217792, 2641807540224, 5429503678976, 10578455953408, 19683000000000, 35184372088832, 60716992766464, 101559956668416, 165216101262848
Offset: 0

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Crossrefs

Cf. A016761.

Programs

  • Magma
    [(2*n)^9: n in [0..20]]; // Vincenzo Librandi, Sep 05 2011
    
  • Maple
    A016749:=n->(2*n)^9: seq(A016749(n), n=0..30); # Wesley Ivan Hurt, Sep 15 2018
  • Mathematica
    Table[(2n)^9, {n, 0, 40}] (* Stefan Steinerberger, Apr 08 2006 *)
    LinearRecurrence[{10,-45,120,-210,252,-210,120,-45, 10, -1}, {0,512, 262144, 10077696, 134217728, 1000000000, 5159780352, 20661046784, 68719476736, 198359290368}, 20] (* Harvey P. Dale, Jan 13 2013 *)
  • PARI
    vector(30, n, n--; (2*n)^9) \\ G. C. Greubel, Sep 15 2018

Formula

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). - Harvey P. Dale, Jan 13 2013
From Amiram Eldar, Oct 11 2020: (Start)
Sum_{n>=1} 1/a(n) = zeta(9)/512.
Sum_{n>=1} (-1)^(n+1)/a(n) = 255*zeta(9)/131072. (End)

Extensions

More terms from Stefan Steinerberger, Apr 08 2006

A016833 a(n) = (4n+2)^9.

Original entry on oeis.org

512, 10077696, 1000000000, 20661046784, 198359290368, 1207269217792, 5429503678976, 19683000000000, 60716992766464, 165216101262848, 406671383849472, 922190162669056, 1953125000000000, 3904305912313344, 7427658739644928, 13537086546263552, 23762680013799936
Offset: 0

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Programs

  • Mathematica
    (4*Range[0,20]+2)^9 (* or *) LinearRecurrence[{10,-45,120,-210,252,-210,120,-45,10,-1},{512,10077696,1000000000,20661046784,198359290368,1207269217792,5429503678976,19683000000000,60716992766464,165216101262848},20] (* Harvey P. Dale, May 26 2018 *)

Formula

From Amiram Eldar, Apr 21 2023: (Start)
a(n) = A016825(n)^9.
a(n) = 2^9*A016761(n).
Sum_{n>=0} 1/a(n) = 511*zeta(9)/262144.
Sum_{n>=0} (-1)^n/a(n) = 277*Pi^9/4227858432. (End)

A017121 a(n) = (8*n + 4)^9.

Original entry on oeis.org

262144, 5159780352, 512000000000, 10578455953408, 101559956668416, 618121839509504, 2779905883635712, 10077696000000000, 31087100296429568, 84590643846578176, 208215748530929664, 472161363286556672, 1000000000000000000, 1999004627104432128, 3802961274698203136
Offset: 0

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Formula

G.f.: 262144*(1+x)*(x^8 + 19672*x^7 + 1736668*x^6 + 19971304*x^5 + 49441990*x^4 + 19971304*x^3 + 1736668*x^2 + 19672*x + 1) / (x-1)^10 . - R. J. Mathar, May 08 2015
From Amiram Eldar, Apr 25 2023: (Start)
a(n) = A017113(n)^9.
a(n) = 2^9*A016833(n) = 2^18*A016761(n).
Sum_{n>=0} 1/a(n) = 511*zeta(9)/134217728.
Sum_{n>=0} (-1)^n/a(n) = 277*Pi^9/2164663517184. (End)

A017337 a(n) = (10*n + 5)^9.

Original entry on oeis.org

1953125, 38443359375, 3814697265625, 78815638671875, 756680642578125, 4605366583984375, 20711912837890625, 75084686279296875, 231616946283203125, 630249409724609375, 1551328215978515625, 3517876291919921875, 7450580596923828125, 14893745087865234375, 28334269484119140625
Offset: 0

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Programs

  • Magma
    [(10*n+5)^9: n in [0..15]]; // Vincenzo Librandi, Aug 02 2011
  • Mathematica
    (10*Range[0,20]+5)^9 (* or *) LinearRecurrence[{10,-45,120,-210,252,-210,120,-45,10,-1},{1953125,38443359375,3814697265625,78815638671875,756680642578125,4605366583984375,20711912837890625,75084686279296875,231616946283203125,630249409724609375},20] (* Harvey P. Dale, Jul 23 2016 *)

Formula

G.f.: 1953125*(x+1)*(x^8 + 19672*x^7 + 1736668*x^6 + 19971304*x^5 + 49441990*x^4 + 19971304*x^3 + 1736668*x^2 + 19672*x + 1)/(x-1)^10. -Colin Barker, Nov 13 2012
From Amiram Eldar, Apr 18 2023: (Start)
a(n) = A017329(n)^9.
a(n) = 5^9 * A016761(n).
Sum_{n>=0} 1/a(n) = 511*zeta(9)/1000000000.
Sum_{n>=0} (-1)^n/a(n) = 277*Pi^9/16128000000000. (End)

A384949 Decimal expansion of Sum_{k>=0} 1/(2*k+1)^9.

Original entry on oeis.org

1, 0, 0, 0, 0, 5, 1, 3, 4, 5, 1, 8, 3, 8, 4, 3, 7, 7, 2, 5, 9, 2, 8, 1, 7, 9, 0, 0, 5, 4, 2, 5, 0, 5, 0, 0, 5, 6, 7, 9, 9, 6, 9, 9, 0, 2, 4, 6, 6, 3, 8, 3, 1, 1, 4, 4, 4, 5, 9, 6, 2, 6, 3, 8, 1, 4, 4, 3, 3, 6, 2, 5, 4, 4, 5, 7, 8, 5, 5, 5, 5, 0, 5, 1, 4, 9, 4, 3, 0, 8, 2, 6, 6, 4, 0, 3, 0, 5, 8, 3
Offset: 1

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Author

Jason Bard, Jul 24 2025

Keywords

Examples

			1.00005134518384377259281790054250500567996990246638...
		

Crossrefs

Programs

  • Maple
    evalf(sum(1/(2*k+1)^9, k=0..infinity), 120);  # Alois P. Heinz, Jul 26 2025
  • Mathematica
    RealDigits[511*Zeta[9]/512, 10, 100][[1]]
  • PARI
    511*zeta(9)/512 \\ Amiram Eldar, Jul 28 2025

Formula

Equals 511*Zeta(9)/512 = 511/512 * A013667.
Equals Sum_{n>=0} 1/A016761(n). - Amiram Eldar, Jul 28 2025
Showing 1-6 of 6 results.