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.

Previous Showing 11-15 of 15 results.

A017520 a(n) = (11*n + 10)^12.

Original entry on oeis.org

1000000000000, 7355827511386641, 1152921504606846976, 39959630797262576401, 614787626176508399616, 5688009063105712890625, 37133262473195501387776, 188031682201497672618081, 784716723734800033386496, 2812664781782894485727281
Offset: 0

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Author

Keywords

Crossrefs

Powers of the form (11*n+10)^m: A017509 (m=1), A017510 (m=2), A017511 (m=3), A017512 (m=4), A017513 (m=5), A017514 (m=6), A017515 (m=7), A017516 (m=8), A017517 (m=9), A017518 (m=10), A017519 (m=11), this sequence (m=12).

Programs

  • GAP
    List([0..20], n-> (11*n+10)^12); # G. C. Greubel, Oct 29 2019
  • Magma
    [(11*n+10)^12: n in [0..20]]; // G. C. Greubel, Oct 29 2019
    
  • Maple
    seq((11*n+10)^12, n=0..20); # G. C. Greubel, Oct 29 2019
  • Mathematica
    (11*Range[0,20]+10)^12 (* Harvey P. Dale, Oct 14 2012 *)
  • Maxima
    makelist((11*n+10)^12,n,0,30); /* Martin Ettl, Oct 21 2012 */
    
  • PARI
    vector(21, n, (11*n-1)^12) \\ G. C. Greubel, Oct 29 2019
    
  • Sage
    [(11*n+10)^12 for n in (0..20)] # G. C. Greubel, Oct 29 2019
    

Formula

From G. C. Greubel, Oct 29 2019: (Start)
G.f.: (1000000000000 + 7342827511386641*x + 1057373746958820643*x^2 + 25545119783261723711*x^3 + 183137251503172391205*x^4 + 488143704350667868074*x^5 + 528998728358533109886*x^6 + 234662813343627300126*x^7 + 39635845367890711434*x^8 + 2102226021911800565*x^9 + 21798715126193071*x^10 + 8916100448243*x^11 + x^12)/(1-x)^13.
E.g.f.: (1000000000000 + 7354827511386641*x + 569105424792036847*x^2 + 6087155460996032566*x^3 + 19243217071043901221*x^4 + 25018123360727376000*x^5 + 15895943833149490132*x^6 + 5437280856006223356*x^7 + 1053961441036472067*x^8 + 117674853236661875*x^9 + 7405264410708505*x^10 + 241373673336906*x^11 + 3138428376721*x^12)*exp(x). (End)

A267541 Expansion of (2 + 4*x + x^2 + x^3 + 2*x^4 + x^5)/(1 - x - x^5 + x^6).

Original entry on oeis.org

2, 6, 7, 8, 10, 13, 17, 18, 19, 21, 24, 28, 29, 30, 32, 35, 39, 40, 41, 43, 46, 50, 51, 52, 54, 57, 61, 62, 63, 65, 68, 72, 73, 74, 76, 79, 83, 84, 85, 87, 90, 94, 95, 96, 98, 101, 105, 106, 107, 109, 112, 116, 117, 118, 120, 123, 127, 128, 129, 131, 134, 138, 139, 140
Offset: 0

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Author

Bruno Berselli, Jan 16 2016

Keywords

Comments

Also, numbers that are congruent to {2, 6, 7, 8, 10} mod 11.
(m^k+1)/11 is a nonnegative integer when
. m is a member of this sequence and k is an odd multiple of 5 (A017329),
. m is a member of A017509 and k is odd but not multiple of 5 (A045572).
If k is even, (m^k+1)/11 is never an integer.
The product of two terms does not belong to the sequence.

Examples

			From the linear recurrence:
(-A267755) ..., -12, -9, -5, -4, -3, -1, 2, 6, 7, 8, 10, 13, ... (A267541)
		

Crossrefs

Cf. A088225: numbers congruent to {2,6,7,8} mod 11.

Programs

  • Magma
    m:=70; R:=PowerSeriesRing(Integers(), m); Coefficients(R!((2+4*x+x^2+x^3+2*x^4+x^5)/(1-x-x^5+x^6)));
    
  • Maple
    gf := (2+4*x+x^2+x^3+2*x^4+x^5)/((1-x)^2*(1+x+x^2+x^3+ x^4)): deg := 64: series(gf,x,deg): seq(coeff(%,x,n), n=0..deg-1); # Peter Luschny, Jan 19 2016
  • Mathematica
    CoefficientList[Series[(2 + 4 x + x^2 + x^3 + 2 x^4 + x^5)/(1 - x - x^5 + x^6), {x, 0, 70}], x]
    LinearRecurrence[{1, 0, 0, 0, 1, -1}, {2, 6, 7, 8, 10, 13}, 70]
    Select[Range[150], MemberQ[{2, 6, 7, 8, 10}, Mod[#, 11]]&]
  • PARI
    Vec((2+4*x+x^2+x^3+2*x^4+x^5)/(1-x-x^5+x^6)+O(x^70))
    
  • Sage
    gf = (2+4*x+x^2+x^3+2*x^4+x^5)/((1-x)^2*(1+x+x^2+x^3+ x^4))
    print(taylor(gf, x, 0, 63).list()) # Peter Luschny, Jan 19 2016

Formula

G.f.: (2 + 4*x + x^2 + x^3 + 2*x^4 + x^5)/((1 - x)^2*(1 + x + x^2 + x^3 + x^4)).
a(n) = a(n-1) + a(n-5) - a(n-6).
a(-n) = -A267755(n-1).

A001536 a(n) = (11*n+1)*(11*n+10).

Original entry on oeis.org

10, 252, 736, 1462, 2430, 3640, 5092, 6786, 8722, 10900, 13320, 15982, 18886, 22032, 25420, 29050, 32922, 37036, 41392, 45990, 50830, 55912, 61236, 66802, 72610, 78660, 84952, 91486, 98262, 105280, 112540, 120042, 127786, 135772, 144000, 152470, 161182, 170136
Offset: 0

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Keywords

Crossrefs

Programs

Formula

a(n) = 242*n + a(n-1) with a(0)=10. - Vincenzo Librandi, Nov 12 2010
G.f.: -2*(5+111*x+5*x^2)/(x-1)^3. - R. J. Mathar, May 30 2022
From Amiram Eldar, Feb 20 2023: (Start)
a(n) = A017401(n)*A017509(n).
Sum_{n>=0} 1/a(n) = cot(Pi/11)*Pi/99.
Product_{n>=0} (1 - 1/a(n)) = cosec(Pi/11)*cos(sqrt(85)*Pi/22).
Product_{n>=0} (1 + 1/a(n)) = cosec(Pi/11)*cos(sqrt(77)*Pi/22). (End)
From Elmo R. Oliveira, Oct 25 2024: (Start)
E.g.f.: exp(x)*(10 + 121*x*(2 + x)).
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n > 2. (End)

A159551 a(n) = 101*n + 10.

Original entry on oeis.org

10, 111, 212, 313, 414, 515, 616, 717, 818, 919, 1020, 1121, 1222, 1323, 1424, 1525, 1626, 1727, 1828, 1929, 2030, 2131, 2232, 2333, 2434, 2535, 2636, 2737, 2838, 2939, 3040, 3141, 3242, 3343, 3444, 3545, 3646, 3747, 3848, 3949, 4050, 4151, 4252, 4353, 4454, 4555
Offset: 0

Views

Author

Robert G. Wilson v, Apr 14 2009

Keywords

Crossrefs

Programs

  • Magma
    [101*n+10: n in [0..50]]; // Vincenzo Librandi, Jul 30 2011
  • Mathematica
    f[n_] := FromDigits[ IntegerDigits[n^3 + n^2 + n - 1, n + 1]]; Array[f, 54]

Formula

From Elmo R. Oliveira, Apr 03 2025: (Start)
G.f.: (10 + 91*x)/(1-x)^2.
E.g.f.: exp(x)*(10 + 101*x).
a(n) = 2*a(n-1) - a(n-2). (End)

Extensions

Offset changed from 1 to 0 by Vincenzo Librandi, Jul 30 2011

A108317 Smallest a(n) such that a(n) n's plus a(n) is prime, or 0 if no such a(n) exists.

Original entry on oeis.org

1, 1, 140, 1, 0, 1, 2, 0, 2, 1, 0, 1, 4, 0, 4, 1, 0, 1, 4, 0, 0, 1, 0, 23, 4, 0, 2, 1, 0, 1, 8, 0, 4198, 497, 0, 1, 2, 0, 8, 1, 0, 1, 0, 0, 2, 1, 0, 35, 2, 0, 2, 1, 0, 0, 2, 0, 4, 1, 0, 1, 2, 0, 4, 17, 0, 1, 64, 0, 2, 1, 0, 1, 14, 0, 2, 0, 0, 1
Offset: 1

Views

Author

Ray G. Opao, Jun 30 2005

Keywords

Comments

Some of the larger entries may only correspond to probable primes.
Some or all of the zero values are merely conjectures. - N. J. A. Sloane
a(n)=0 for n = 3m+2 (1<=m) (they are all divisible by 3) or n=11m+10 (1<=m<9) (they are all divisible by 11) and if a(n) is not 0 then n and a(n) are of opposite parity. - Robert G. Wilson v and Rick L. Shepherd, Jul 28 2005
The sequence continues: 0,4490,1,0,13,14,0,0,1,0,349,10,0,86,2539,0,1,4,0,124,1,0,1,4,0,2,1,0,1,2,0,302,1,0,83,2,0,2,5,0,a(120)>5364,2,0,278,5,0,...,. - Robert G. Wilson v, Jul 28 2005
a(79)>14179. - Robert G. Wilson v, Jul 28 2005

Examples

			a(13)=4: 4 13s plus 4 = 13131313+4 = 13131317, which is prime.
		

Crossrefs

Cf. A006093 (primes minus 1), A016789 (3n + 2), A017509 (11n + 10).

Programs

  • Mathematica
    f[n_] := If[(n > 4 && Mod[n, 3] == 2) || (n > 20 && Mod[n, 11] == 10), k = 0, If[n == 1, k = 1, Block[{id = IntegerDigits[n]}, k = Mod[n, 2] + 1; While[ !PrimeQ[ FromDigits[ Flatten[ Table[id, {k}]]] + k], k += 2]]]; k]; Table[ f[n], {n, 100}] (* only good for n<109 *) (* Robert G. Wilson v, Jun 30 2005 *)
  • PARI
    /* for nonzero terms */ a(n) = m=1;pr=n;while(!isprime(pr+m),m++;pr=eval(concat(Str(pr),n)));m \\ Rick L. Shepherd, Jul 26 2005

Formula

a(A016789(n)) = a(A017509(n)) = 0 for n >= 1. a(n) = 1 iff n is a term of A006093. - Rick L. Shepherd, Jul 26 2005

Extensions

a(33) - a(78) from Robert G. Wilson v with guidance from Rick L. Shepherd, Jul 28 2005
Previous Showing 11-15 of 15 results.