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.

A139634 a(n) = 10*2^(n-1) - 9.

Original entry on oeis.org

1, 11, 31, 71, 151, 311, 631, 1271, 2551, 5111, 10231, 20471, 40951, 81911, 163831, 327671, 655351, 1310711, 2621431, 5242871, 10485751, 20971511, 41943031, 83886071, 167772151, 335544311, 671088631, 1342177271, 2684354551
Offset: 1

Views

Author

Gary W. Adamson, Apr 29 2008

Keywords

Comments

Binomial transform of [1, 10, 10, 10,...].
A007318 * [1, 10, 10, 10,...].
The binomial transform of [1, c, c, c,...] has the terms a(n)=1-c+c*2^(n-1) if the offset 1 is chosen. The o.g.f. of the a(n) is x{1+(c-2)x}/{(2x-1)(x-1)}. This applies to A139634 with c=10, to A139635 with c=11, to A139697 with c=12, to A139698 with c=25 and to A099003, A139700, A139701 accordingly. - R. J. Mathar, May 11 2008

Examples

			a(4) = 71 = (1, 3, 3, 1) dot (1, 10, 10, 10) = (1 + 30 + 30 + 10).
		

Crossrefs

Cf. A007318.

Programs

Formula

a(n) = 2*a(n-1) + 9, with n>1, a(1)=1. - Vincenzo Librandi, Nov 24 2010
From Colin Barker, Oct 10 2013: (Start)
a(n) = 3*a(n-1) - 2*a(n-2).
G.f.: x*(8*x+1) / ((x-1)*(2*x-1)). (End)

Extensions

More terms from Vladimir Joseph Stephan Orlovsky, Dec 17 2008
Simpler definition from Jon E. Schoenfield, Jun 23 2010

A099003 Number of 4 X n 0-1 matrices avoiding simultaneously the right angled numbered polyomino patterns (ranpp) (00;1), (10;0) and (11;0).

Original entry on oeis.org

1, 16, 46, 106, 226, 466, 946, 1906, 3826, 7666, 15346, 30706, 61426, 122866, 245746, 491506, 983026, 1966066, 3932146, 7864306, 15728626, 31457266, 62914546, 125829106, 251658226, 503316466, 1006632946, 2013265906, 4026531826
Offset: 0

Views

Author

Sergey Kitaev, Nov 13 2004

Keywords

Comments

An occurrence of a ranpp (xy;z) in a matrix A=(a(i,j)) is a triple (a(i1,j1), a(i1,j2), a(i2,j1)) where i1 < i2, j1 < j2 and these elements are in the same relative order as those in the triple (x,y,z). In general, the number of m X n 0-1 matrices in question is given by 2^(m+n) - 2^m - 2^n + 2.
Binomial transform of 1,15,15,... (15 infinitely repeated). - Gary W. Adamson, Apr 29 2008
The binomial transform of [1, c, c, c, ...] has the terms a(n) = 1 - c + c*2^(n-1) if the offset 1 is chosen. The o.g.f. of the a(n) is x*(1+(c-2)x)/((2x-1)*(x-1)). This applies to A139634 with c=10, to A139635 with c=11, to A139697 with c=12, to A139698 with c=25 and to A099003, A139700, A139701 accordingly. - R. J. Mathar, May 11 2008

Crossrefs

Cf. A048489 (m=3).

Programs

  • Mathematica
    LinearRecurrence[{3,-2},{1,16},40] (* Harvey P. Dale, May 20 2018 *)

Formula

a(n) = 15*2^n - 14.
O.g.f.: (1+13x)/((x-1)(2x-1)). - R. J. Mathar, May 06 2008

A139635 Binomial transform of [1, 11, 11, 11, ...].

Original entry on oeis.org

1, 12, 34, 78, 166, 342, 694, 1398, 2806, 5622, 11254, 22518, 45046, 90102, 180214, 360438, 720886, 1441782, 2883574, 5767158, 11534326, 23068662, 46137334, 92274678, 184549366, 369098742, 738197494, 1476394998, 2952790006, 5905580022, 11811160054
Offset: 1

Views

Author

Gary W. Adamson, Apr 29 2008

Keywords

Comments

A007318 * [1, 11, 11, 11, ...].
The binomial transform of [1, c, c, c, ...] has the terms a(n) = 1 - c + c*2^(n-1) if the offset 1 is chosen. The o.g.f. of the a(n) is x*(1+(c-2)*x)/((2x-1)*(x-1)). This applies to A139634 with c=10, to A139635 with c=11, to A139697 with c=12, to A139698 with c=25 and to A099003, A139700, A139701 accordingly. - R. J. Mathar, May 11 2008

Examples

			a(4) = 78 = (1, 3, 3, 1) dot (1, 11, 11, 11) = (1 + 33 + 33 + 11).
		

Crossrefs

Cf. A139634.

Programs

  • Maple
    seq(11*2^(n-1)-10,n=1.. 25); # Emeric Deutsch, May 03 2008
  • Mathematica
    a=1; lst={a}; k=11; Do[a+=k; AppendTo[lst, a]; k+=k, {n, 0, 5!}]; lst (* Vladimir Joseph Stephan Orlovsky, Dec 17 2008 *)
    CoefficientList[Series[(9 x + 1)/((x - 1) (2 x - 1)), {x, 0, 40}], x] (* Vincenzo Librandi, Mar 13 2014 *)
    LinearRecurrence[{3,-2},{1,12},40] (* Harvey P. Dale, Oct 26 2015 *)
  • PARI
    Vec(x*(9*x+1)/((x-1)*(2*x-1)) + O(x^100)) \\ Colin Barker, Mar 11 2014

Formula

a(n) = 11*2^(n-1) - 10. - Emeric Deutsch, May 03 2008
a(n) = 2*a(n-1) + 10, with n > 1, a(1)=1. - Vincenzo Librandi, Nov 24 2010
From Colin Barker, Mar 11 2014: (Start)
a(n) = 3*a(n-1) - 2*a(n-2).
G.f.: x*(9*x+1) / ((x-1)*(2*x-1)). (End)

Extensions

More terms from Emeric Deutsch, May 03 2008
More terms from Colin Barker, Mar 11 2014

A139698 Binomial transform of [1, 25, 25, 25, ...].

Original entry on oeis.org

1, 26, 76, 176, 376, 776, 1576, 3176, 6376, 12776, 25576, 51176, 102376, 204776, 409576, 819176, 1638376, 3276776, 6553576, 13107176, 26214376, 52428776, 104857576, 209715176, 419430376, 838860776, 1677721576, 3355443176, 6710886376, 13421772776, 26843545576
Offset: 1

Views

Author

Gary W. Adamson, Apr 29 2008

Keywords

Comments

The binomial transform of [1, c, c, c, ...] has the terms a(n)=1-c+c*2^(n-1) if the offset 1 is chosen. The o.g.f. of the a(n) is x{1+(c-2)x}/{(2x-1)(x-1)}. This applies to A139634 with c=10, to A139635 with c=11, to A139697 with c=12, to A139698 with c=25 and to A099003, A139700, A139701 accordingly. - R. J. Mathar, May 11 2008

Examples

			a(3) = 76 = (1, 2, 1) dot (1, 25, 25) = (1 + 50 + 25).
		

Crossrefs

Programs

  • Magma
    [25*2^(n-1)-24 : n in [1..40]]; // Wesley Ivan Hurt, Jan 17 2017
  • Maple
    seq(25*2^(n-1)-24,n=1..25); # Emeric Deutsch, May 03 2008
  • Mathematica
    LinearRecurrence[{3,-2},{1,26},40] (* Harvey P. Dale, Jul 25 2021 *)
  • PARI
    Vec(x*(23*x+1)/((x-1)*(2*x-1)) + O(x^100)) \\ Colin Barker, Mar 11 2014
    

Formula

A007318 * [1, 25, 25, 25, ...].
a(n) = 25*2^(n-1)-24. - Emeric Deutsch, May 03 2008
a(n) = 2*a(n-1) + 24 (with a(1)=1). - Vincenzo Librandi, Nov 24 2010
a(n) = 3*a(n-1)-2*a(n-2). G.f.: x*(23*x+1) / ((x-1)*(2*x-1)). - Colin Barker, Mar 11 2014

Extensions

More terms from Emeric Deutsch, May 03 2008
More terms from Colin Barker, Mar 11 2014

A139700 Binomial transform of [1, 30, 30, 30, ...].

Original entry on oeis.org

1, 31, 91, 211, 451, 931, 1891, 3811, 7651, 15331, 30691, 61411, 122851, 245731, 491491, 983011, 1966051, 3932131, 7864291, 15728611, 31457251, 62914531, 125829091, 251658211, 503316451, 1006632931, 2013265891, 4026531811, 8053063651, 16106127331
Offset: 1

Views

Author

Gary W. Adamson, Apr 29 2008

Keywords

Comments

The binomial transform of [1, c, c, c, ...] has the terms a(n) = 1 - c + c*2^(n-1) if the offset 1 is chosen. The o.g.f. of the a(n) is x{1+(c-2)x}/{(2x-1)(x-1)}. This applies to A139634 with c=10, to A139635 with c=11, to A139697 with c=12, to A139698 with c=25 and to A099003, A139700, A139701 accordingly. - R. J. Mathar, May 11 2008

Examples

			a(3) = 91 = (1, 2, 1) dot (1, 30, 30) = (1 + 60 + 30).
		

Crossrefs

Programs

  • Maple
    seq(30*2^(n-1)-29,n=1..27); # Emeric Deutsch, May 07 2008
  • Mathematica
    LinearRecurrence[{3,-2},{1,31},30] (* Harvey P. Dale, Apr 18 2018 *)
  • PARI
    Vec(x*(28*x+1)/((x-1)*(2*x-1)) + O(x^100)) \\ Colin Barker, Mar 11 2014

Formula

A007318 * [1, 30, 30, 30, ...].
a(n) = 30*2^(n-1) - 29. - Emeric Deutsch, May 07 2008
a(n) = 2*a(n-1) + 29 (with a(1)=1). - Vincenzo Librandi, Nov 24 2010
From Colin Barker, Mar 11 2014: (Start)
a(n) = 3*a(n-1) - 2*a(n-2).
G.f.: x*(28*x+1) / ((x-1)*(2*x-1)). (End)

Extensions

More terms from Emeric Deutsch, May 07 2008
More terms from Colin Barker, Mar 11 2014

A139701 Binomial transform of [1, 100, 100, 100, ...].

Original entry on oeis.org

1, 101, 301, 701, 1501, 3101, 6301, 12701, 25501, 51101, 102301, 204701, 409501, 819101, 1638301, 3276701, 6553501, 13107101, 26214301, 52428701, 104857501, 209715101, 419430301, 838860701, 1677721501, 3355443101, 6710886301, 13421772701, 26843545501
Offset: 1

Views

Author

Gary W. Adamson, Apr 29 2008

Keywords

Comments

The binomial transform of [1, c, c, c, ...] has the terms a(n)=1-c+c*2^(n-1) if the offset 1 is chosen. The o.g.f. of a(n) is x{1+(c-2)x}/{(2x-1)(x-1)}. This applies to A139634 with c=10, to A139635 with c=11, to A139697 with c=12, to A139698 with c=25 and to A099003, A139700, A139701 accordingly. - R. J. Mathar, May 11 2008

Examples

			a(3) = 301 = (1, 2, 1) dot (1, 100, 100) = (1 + 200 + 100).
		

Crossrefs

Programs

  • Magma
    [100*2^(n-1)-99 : n in [1..30]]; // Wesley Ivan Hurt, Aug 16 2016
  • Maple
    a:=proc(n) options operator, arrow: 100*2^(n-1)-99 end proc: seq(a(n), n=1.. 30); # Emeric Deutsch, May 03 2008
  • Mathematica
    100*2^(Range[30] - 1) - 99 (* Wesley Ivan Hurt, Aug 16 2016 *)
    LinearRecurrence[{3, -2}, {1, 101}, 40] (* Vincenzo Librandi, Aug 17 2016 *)
  • PARI
    Vec(x*(98*x+1)/((x-1)*(2*x-1)) + O(x^100)) \\ Colin Barker, Mar 11 2014
    

Formula

A007318 * [1, 100, 100, 100, ...].
a(n) = 100*2^(n-1)-99. - Emeric Deutsch, May 03 2008
a(n) = 2*a(n-1)+99 for n > 1. [Vincenzo Librandi, Nov 24 2010]
a(n) = 3*a(n-1) - 2*a(n-2) for n > 2. G.f.: x*(98*x+1) / ((x-1)*(2*x-1)). - Colin Barker, Mar 11 2014

Extensions

More terms from Emeric Deutsch, May 03 2008
More terms from Colin Barker, Mar 11 2014

A062001 Table by antidiagonals of n-Stohr sequences: T(n,k) is least positive integer not the sum of at most n distinct terms in the n-th row from T(n,1) through to T(n,k-1).

Original entry on oeis.org

1, 2, 1, 3, 2, 1, 4, 4, 2, 1, 5, 7, 4, 2, 1, 6, 10, 8, 4, 2, 1, 7, 13, 15, 8, 4, 2, 1, 8, 16, 22, 16, 8, 4, 2, 1, 9, 19, 29, 31, 16, 8, 4, 2, 1, 10, 22, 36, 46, 32, 16, 8, 4, 2, 1, 11, 25, 43, 61, 63, 32, 16, 8, 4, 2, 1, 12, 28, 50, 76, 94, 64, 32, 16, 8, 4, 2, 1, 13, 31, 57, 91, 125, 127, 64, 32, 16, 8, 4, 2, 1
Offset: 1

Views

Author

Henry Bottomley, May 29 2001

Keywords

Examples

			Array begins as:
  1, 2, 3, 4,  5,  6,  7,   8,   9, ... A000027;
  1, 2, 4, 7, 10, 13, 16,  19,  22, ... A033627;
  1, 2, 4, 8, 15, 22, 29,  36,  43, ... A026474;
  1, 2, 4, 8, 16, 31, 46,  61,  76, ... A051039;
  1, 2, 4, 8, 16, 32, 63,  94, 125, ... A051040;
  1, 2, 4, 8, 16, 32, 64, 127, 190, ... ;
  1, 2, 4, 8, 16, 32, 64, 128, 255, ... ;
  1, 2, 4, 8, 16, 32, 64, 128, 256, ... ;
  1, 2, 4, 8, 16, 32, 64, 128, 256, ... ;
Antidiagonal triangle begins as:
   1;
   2,  1;
   3,  2,  1;
   4,  4,  2,  1;
   5,  7,  4,  2,   1;
   6, 10,  8,  4,   2,   1;
   7, 13, 15,  8,   4,   2,  1;
   8, 16, 22, 16,   8,   4,  2,  1;
   9, 19, 29, 31,  16,   8,  4,  2,  1;
  10, 22, 36, 46,  32,  16,  8,  4,  2, 1;
  11, 25, 43, 61,  63,  32, 16,  8,  4, 2, 1;
  12, 28, 50, 76,  94,  64, 32, 16,  8, 4, 2, 1;
  13, 31, 57, 91, 125, 127, 64, 32, 16, 8, 4, 2, 1;
		

Crossrefs

Diagonals include A000079, A000225, A033484, A036563, A048487.
A048483 can be seen as half this table.

Programs

  • Mathematica
    T[n_, k_]:= If[kG. C. Greubel, May 03 2022 *)
  • SageMath
    def A062001(n,k):
        if (kA062001(n,k) for k in (1..n)] for n in (1..15)]) # G. C. Greubel, May 03 2022

Formula

If k <= n+1 then A(n, k) = 2^(k-1), while if k > n+1, A(n, k) = (2^n - 1)*(k - n) + 1 (array).
T(n, k) = A(k, n-k+1) (antidiagonals).
T(2*n-1, n) = A000079(n-1), n >= 1.
T(2*n, n) = A000079(n), n >= 1.
T(2*n+1, n) = A000225(n+1), n >= 1.
T(2*n+2, n) = A033484(n), n >= 1.
T(2*n+3, n) = A036563(n+3), n >= 1.
T(2*n+4, n) = A048487(n), n >= 1.
From G. C. Greubel, May 03 2022: (Start)
T(n, k) = (2^k - 1)*(n-2*k+1) + 1 for k < n/2, otherwise 2^(n-k).
T(2*n+5, n) = A048488(n), n >= 1.
T(2*n+6, n) = A048489(n), n >= 1.
T(2*n+7, n) = A048490(n), n >= 1.
T(2*n+8, n) = A048491(n), n >= 1.
T(2*n+9, n) = A139634(n), n >= 1.
T(2*n+10, n) = A139635(n), n >= 1.
T(2*n+11, n) = A139697(n), n >= 1. (End)

A173872 Primes of the form 12*2^n - 11.

Original entry on oeis.org

13, 37, 181, 373, 757, 3061, 6133, 12277, 196597, 1572853, 25165813, 805306357, 3221225461, 6442450933, 12884901877, 26388279066613, 3377699720527861, 1813388729421943762059253
Offset: 1

Views

Author

Vincenzo Librandi, Mar 05 2010

Keywords

Crossrefs

Programs

  • Maple
    select(isprime,[seq(12*2^n-11,n=1..1000)]); # Robert Israel, Aug 20 2014
  • Mathematica
    Select[NestList[2#+11&,13,80],PrimeQ] (* Harvey P. Dale, Jun 18 2013 *)
Showing 1-8 of 8 results.