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 1-9 of 9 results.

A048487 a(n) = T(4,n), array T given by A048483.

Original entry on oeis.org

1, 6, 16, 36, 76, 156, 316, 636, 1276, 2556, 5116, 10236, 20476, 40956, 81916, 163836, 327676, 655356, 1310716, 2621436, 5242876, 10485756, 20971516, 41943036, 83886076, 167772156, 335544316, 671088636, 1342177276, 2684354556, 5368709116, 10737418236, 21474836476
Offset: 0

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Author

Keywords

Comments

Row sums of triangle A131113. - Gary W. Adamson, Jun 15 2007
a(n) = sum of (n+1)-th row terms of triangle A134636. This sequence is the binomial transform of 1, 5, 5, (5 continued). - Gary W. Adamson, Nov 04 2007
Row sums of triangle A135856. - Gary W. Adamson, Dec 01 2007

Crossrefs

Cf. A010716 (n-th difference of a(n), a(n-1), ..., a(0)).
Diagonal of A062001.
A column of A119726.

Programs

Formula

a(n) = 5*2^n - 4. - Henry Bottomley, May 29 2001
a(n) = 2*a(n-1) + 4 for n > 0 with a(0) = 1. - Paul Barry, Aug 25 2004
From Colin Barker, Sep 13 2012: (Start)
a(n) = 3*a(n-1) - 2*a(n-2) for n >= 2.
G.f.: (1 + 3*x)/((1 - x)*(1 - 2*x)). (End)
a(n) = A123208(2*n). - Philippe Deléham, Apr 15 2013
E.g.f.: exp(x)*(5*exp(x) - 4). - Stefano Spezia, Oct 03 2023

A048490 a(n) = T(7,n), array T given by A048483.

Original entry on oeis.org

1, 9, 25, 57, 121, 249, 505, 1017, 2041, 4089, 8185, 16377, 32761, 65529, 131065, 262137, 524281, 1048569, 2097145, 4194297, 8388601, 16777209, 33554425, 67108857, 134217721, 268435449, 536870905, 1073741817, 2147483641, 4294967289, 8589934585
Offset: 0

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Author

Keywords

Comments

n-th difference of a(n), a(n-1), ..., a(0) is (8, 8, 8, ...).

Programs

Formula

a(n) = 8 * 2^n - 7. - Ralf Stephan, Jan 09 2009
Equals binomial transform of [1, 8, 8, 8, ...]. - Gary W. Adamson, Apr 29 2008
a(n) = 2*a(n-1) + 7 for n > 0, a(0)=1. - Vincenzo Librandi, Aug 06 2010
For n>=1, a(n) = 6<+>(n+3), where the operation <+> is defined in A206853. - Vladimir Shevelev, Feb 17 2012
From Colin Barker, Nov 26 2014: (Start)
a(n) = 3*a(n-1) - 2*a(n-2).
G.f.: (6*x+1) / ((x-1)*(2*x-1)). (End)

Extensions

More terms from Colin Barker, Nov 26 2014

A048491 a(n) = T(8,n), array T given by A048483.

Original entry on oeis.org

1, 10, 28, 64, 136, 280, 568, 1144, 2296, 4600, 9208, 18424, 36856, 73720, 147448, 294904, 589816, 1179640, 2359288, 4718584, 9437176, 18874360, 37748728, 75497464, 150994936, 301989880, 603979768, 1207959544, 2415919096
Offset: 0

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Author

Keywords

Comments

n-th difference of a(n), a(n-1), ..., a(0) is (9, 9, 9, ...).

Programs

Formula

a(n) = 9 * 2^n - 8. - Ralf Stephan
Equals binomial transform of [1, 9, 9, 9, ...]. - Gary W. Adamson, Apr 29 2008
a(n) = 2*a(n-1) + 8, with a(0)=1. - Vincenzo Librandi, Aug 06 2010
a(n) = 2*A053209(n), n>0. - Philippe Deléham, Apr 15 2013
a(n) = 3*a(n-1) - 2*a(n-2) with a(0)=1, a(1)=10. - Philippe Deléham, Apr 15 2013
G.f.: (1+7*x)/((1-x)*(1-2*x)). - Philippe Deléham, Apr 15 2013

A048488 a(n) = 6*2^n - 5.

Original entry on oeis.org

1, 7, 19, 43, 91, 187, 379, 763, 1531, 3067, 6139, 12283, 24571, 49147, 98299, 196603, 393211, 786427, 1572859, 3145723, 6291451, 12582907, 25165819, 50331643, 100663291, 201326587, 402653179, 805306363, 1610612731
Offset: 0

Views

Author

Clark Kimberling, Dec 11 1999

Keywords

Comments

a(n) = T(5, n), array T given by A048483.
Sequence is generated by the Northwest (NW) direction of circles put around circle(s). See illustration. - Odimar Fabeny, Aug 09 2008

Examples

			a(2) = 6 * 2^2 - 5 = 6 * 4 - 5 = 24 - 5 = 19.
a(3) = 6 * 2^3 - 5 = 6 * 8 - 5 = 48 - 5 = 43.
		

Crossrefs

n-th difference of a(n), a(n-1), ..., a(0) is (6, 6, 6, ...).
Cf. A000079, A007283. - Omar E. Pol, Dec 21 2008

Programs

Formula

a(n) = 2*a(n-1) + 5, n > 0, a(0) = 1. - Paul Barry, Aug 25 2004
Equals binomial transform of [1, 6, 6, 6, ...]. - Gary W. Adamson, Apr 29 2008
a(n) = A000079(n)*6 - 5 = A007283(n)*2 - 5. - Omar E. Pol, Dec 21 2008
From Colin Barker, Sep 17 2012: (Start)
a(n) = 3*2^(1+n) - 5. a(n) = 3*a(n-1) - 2*a(n-2).
G.f.: (1+4*x)/((1-x)*(1-2*x)). (End)
a(n + 1) = 3 * 2^n - 5 = 1 + 2 * (Sum_{i=0..n-1} 3i) for n > 0. - Gerasimov Sergey and Alonso del Arte, May 03 2014
a(n) = A000225(n+1)+4*A000225(n). - R. J. Mathar, Feb 27 2019

Extensions

Simpler definition from Ralf Stephan

A048489 a(n) = 7 * 2^n - 6.

Original entry on oeis.org

1, 8, 22, 50, 106, 218, 442, 890, 1786, 3578, 7162, 14330, 28666, 57338, 114682, 229370, 458746, 917498, 1835002, 3670010, 7340026, 14680058, 29360122, 58720250, 117440506, 234881018, 469762042, 939524090, 1879048186
Offset: 0

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Author

Keywords

Comments

Number of 3 X n 0-1 matrices avoiding simultaneously the right angled numbered polyomino patterns (ranpp) (00;1), (10;0) and (11;0). 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 i1Sergey Kitev, Nov 13 2004
Row sums of triangle A131115. - N. J. A. Sloane, Nov 10 2007
Equals binomial transform of [1, 7, 7, 7, ...]. - Gary W. Adamson, Apr 28 2008
Number of variations of a Componium barrel which produces n phrases. This sequence describes the variations produced by the Componium, a historical mechanical organ. Another way of describing it is: Number of base 8 n-digit numbers produced by repeating or advancing along this 14-step cycle: (0,1,2,3,4,5,6,7,6,5,4,3,2,1). Subset of A126362. - Jim Bumgardner, Dec 10 2013
a(n) = the sum of the terms in row(n) in a triangle with first column T(n,0)=
1+2*n and diagonal T(n,n)=1+4*n with T(i,j)=T(i-1,j-1) + T(i-1,j). - J. M. Bergot, May 11 2018

Crossrefs

a(n)=T(6, n), array T given by A048483.
n-th difference of a(n), a(n-1), ..., a(0) is (7, 7, 7, ...).
Cf. A131115.

Programs

  • Maple
    A048489:=n->7*2^n-6: seq(A048489(n), n=0..40); # Wesley Ivan Hurt, Apr 18 2017
  • Mathematica
    CoefficientList[Series[(1 + 5 x)/((2 x - 1) (x - 1)), {x, 0, 28}], x] (* Michael De Vlieger, May 22 2018 *)
    7*2^Range[0,30]-6 (* or *) LinearRecurrence[{3,-2},{1,8},30] (* Harvey P. Dale, May 19 2019 *)
  • PARI
    a(n)=7<Charles R Greathouse IV, Dec 10 2013

Formula

a(n) = A000079(n)*7-6 = A005009(n)-6. - Omar E. Pol, Dec 21 2008
a(n) = 2*a(n-1)+6 with n>0, a(0)=1. - Vincenzo Librandi, Aug 06 2010
G.f.: ( 1+5*x ) / ( (2*x-1)*(x-1) ). - R. J. Mathar, Oct 21 2012
a(n) = A063757(2*n). - Philippe Deléham, Apr 13 2013

A048493 a(n) = (n+1)*2^n - n.

Original entry on oeis.org

1, 3, 10, 29, 76, 187, 442, 1017, 2296, 5111, 11254, 24565, 53236, 114675, 245746, 524273, 1114096, 2359279, 4980718, 10485741, 22020076, 46137323, 96468970, 201326569, 419430376, 872415207, 1811939302, 3758096357, 7784628196, 16106127331, 33285996514
Offset: 0

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Author

Keywords

Comments

Old definition was: "a(n) = T(n,n), array T given by A048483".
Also the number of connected induced subgraphs in the n-sunlet graph. - Eric W. Weisstein, May 25 2017

Crossrefs

Cf. A058877.

Programs

  • Magma
    [(n+1)*2^n-n: n in [0..30]]; // Vincenzo Librandi, Sep 26 2011
    
  • Mathematica
    Table[(n + 1) 2^n - n, {n, 20}] (* Eric W. Weisstein, May 25 2017 *)
    Table[2^n + (2^n - 1) n, {n, 20}] (* Eric W. Weisstein, May 25 2017 *)
    LinearRecurrence[{6, -13, 12, -4}, {3, 10, 29, 76}, 20] (* Eric W. Weisstein, May 25 2017 *)
  • PARI
    Vec(-(4*x^3-5*x^2+3*x-1)/((x-1)^2*(2*x-1)^2) + O(x^100)) \\ Colin Barker, Nov 26 2014

Formula

a(n) = (n+1)*2^n-n. - Vladeta Jovovic, Feb 28 2003
a(n) = 5*a(n-1)-7*a(n-2)-a(n-3)+8*a(n-4)-4*a(n-5). - Colin Barker, Nov 26 2014
G.f.: -(4*x^3-5*x^2+3*x-1) / ((x-1)^2*(2*x-1)^2). - Colin Barker, Nov 26 2014

Extensions

Description changed to more explicit formula by Eric W. Weisstein, May 25 2017

A119726 Triangular array read by rows: T(n,1) = T(n,n) = 1, T(n,k) = 4*T(n-1, k-1) + 2*T(n-1, k).

Original entry on oeis.org

1, 1, 1, 1, 6, 1, 1, 16, 26, 1, 1, 36, 116, 106, 1, 1, 76, 376, 676, 426, 1, 1, 156, 1056, 2856, 3556, 1706, 1, 1, 316, 2736, 9936, 18536, 17636, 6826, 1, 1, 636, 6736, 30816, 76816, 109416, 84196, 27306, 1, 1, 1276, 16016, 88576, 276896, 526096, 606056, 391396, 109226, 1
Offset: 1

Views

Author

Zerinvary Lajos, Jun 14 2006

Keywords

Comments

Second column is A048487.
Second diagonal is A020989.

Examples

			Triangle begins as:
  1;
  1,    1;
  1,    6,     1;
  1,   16,    26,     1;
  1,   36,   116,   106,      1;
  1,   76,   376,   676,    426,      1;
  1,  156,  1056,  2856,   3556,   1706,      1;
  1,  316,  2736,  9936,  18536,  17636,   6826,      1;
  1,  636,  6736, 30816,  76816, 109416,  84196,  27306,      1;
  1, 1276, 16016, 88576, 276896, 526096, 606056, 391396, 109226, 1;
		

References

  • TERMESZET VILAGA XI.TERMESZET-TUDOMANY DIAKPALYAZAT 133.EVF. 6.SZ. jun. 2002. Vegh Lea (and Vegh Erika): "Pascal-tipusu haromszogek" http://www.kfki.hu/chemonet/TermVil/tv2002/tv0206/tartalom.html

Crossrefs

Programs

  • Magma
    function T(n,k)
      if k eq 1 or k eq n then return 1;
      else return 4*T(n-1,k-1) + 2*T(n-1,k);
      end if;
      return T;
    end function;
    [T(n,k): k in [1..n], n in [1..12]]; // G. C. Greubel, Nov 18 2019
    
  • Maple
    T:= proc(n, k) option remember;
          if k=1 and k=n then 1
        else 4*T(n-1, k-1) + 2*T(n-1, k)
          fi
    end: seq(seq(T(n, k), k=1..n), n=1..12); # G. C. Greubel, Nov 18 2019
  • Mathematica
    T[n_, k_]:= T[n, k]= If[k==1 || k==n, 1, 4*T[n-1, k-1] + 2*T[n-1, k]]; Table[T[n,k], {n,10}, {k,n}]//Flatten (* G. C. Greubel, Nov 18 2019 *)
  • PARI
    T(n,k) = if(k==1 || k==n, 1, 4*T(n-1,k-1) + 2*T(n-1,k));
    
  • Sage
    @CachedFunction
    def T(n, k):
        if (k==1 or k==n): return 1
        else: return 4*T(n-1, k-1) + 2*T(n-1, k)
    [[T(n, k) for k in (1..n)] for n in (1..12)] # G. C. Greubel, Nov 18 2019

Extensions

Edited by Don Reble, Jul 24 2006

A048492 a(n) = ( 8*(2^n) - n^2 - 3*n - 6 )/2.

Original entry on oeis.org

1, 3, 8, 20, 47, 105, 226, 474, 977, 1991, 4028, 8112, 16291, 32661, 65414, 130934, 261989, 524115, 1048384, 2096940, 4194071, 8388353, 16776938, 33554130, 67108537, 134217375, 268435076, 536870504, 1073741387, 2147483181
Offset: 0

Views

Author

Keywords

Comments

Partial sums of A000325, starting at n=1. - Klaus Brockhaus, Oct 13 2008

Crossrefs

a(n)=T(0, n)+T(1, n-1)+...+T(n, 0), array T given by A048483.
Cf. A000325 (2^n - n), A145070. - Klaus Brockhaus, Oct 13 2008

Programs

  • ARIBAS
    a:=0; for n:=1 to 30 do a:=a+2**n-n; write(a, ","); end; # Klaus Brockhaus, Oct 13 2008
    
  • Magma
    [( 8*(2^n) -n^2 -3*n -6 )/2: n in [0..30]]; // Vincenzo Librandi, Sep 23 2011
    
  • Mathematica
    lst={};s=0;Do[s+=2^n-n;AppendTo[lst, s], {n, 5!}];lst (* Vladimir Joseph Stephan Orlovsky, Sep 30 2008 *)
    Table[(8*2^n-n^2-3n-6)/2,{n,0,30}]
    LinearRecurrence[{5,-9,7,-2},{1,3,8,20},40] (* Harvey P. Dale, Aug 28 2019 *)
  • PARI
    Vec((2*x^2-2*x+1) / ((x-1)^3*(2*x-1)) + O(x^100)) \\ Colin Barker, Oct 27 2014

Formula

a(0) = 1; a(n) = a(n-1) + 2^(n+1) - (n+1) for n > 0. - Klaus Brockhaus, Oct 13 2008
From Colin Barker, Oct 27 2014: (Start)
a(n) = (-2+2^(2+n)-1/2*(1+n)*(2+n)).
a(n) = 5*a(n-1)-9*a(n-2)+7*a(n-3)-2*a(n-4).
G.f.: (2*x^2-2*x+1) / ((x-1)^3*(2*x-1)).
(End)

Extensions

Better description from Frank Ellermann, Mar 16 2002
Corrected by T. D. Noe, Nov 08 2006

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)
Showing 1-9 of 9 results.