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 1-10 of 16 results. Next

A159742 If an array is made of columns of -nacci sequences (Fibonacci, tribonacci, etc.), all starting with 1,1,2,..., the NW-to-SE diagonals can be extended by computation. This sequence is diagonal 6. See A159741 for details.

Original entry on oeis.org

13, 44, 108, 236, 492, 1004, 2028, 4076, 8172, 16364, 32748, 65516, 131052, 262124, 524268, 1048556, 2097132, 4194284, 8388588, 16777196, 33554412, 67108844, 134217708, 268435436, 536870892, 1073741804, 2147483628, 4294967276, 8589934572, 17179869164
Offset: 1

Views

Author

Al Hakanson (hawkuu(AT)gmail.com), Apr 20 2009

Keywords

Programs

  • Magma
    [13] cat [4*(2^(n+2) - 5): n in [2..30]]; // G. C. Greubel, May 22 2018
  • Maple
    T := proc(n,m) option remember ; if n < 0 then 0; elif n <= 1 then 1; elif n = 2 then 2; else add(procname(n-i,m),i=1..m) ; fi: end: A159742 := proc(n) T(n+5,n+1) ; end: seq(A159742(n),n=1..40) ; # R. J. Mathar, Apr 22 2009
  • Mathematica
    CoefficientList[Series[(2*z^2 + 5*z + 13)/(2*z^2 - 3*z + 1), {z, 0, 100}], z] (* Vladimir Joseph Stephan Orlovsky, Jul 08 2011 *)
    Join[{13}, Table[4*(2^(n + 2) - 5), {n, 2, 50}]] (* G. C. Greubel, May 22 2018 *)
    LinearRecurrence[{3,-2},{13,44,108},30] (* Harvey P. Dale, Jul 10 2018 *)
  • PARI
    for(n=1, 30, print1(if(n==1, 13, 4*(2^(n+2) - 5)), ", ")) \\ G. C. Greubel, May 22 2018
    

Formula

From R. J. Mathar, Apr 22 2009: (Start)
a(n) = 3*a(n-1) - 2*a(n-2), n>3.
a(n) = 16*2^n - 20, n>1. (End)

Extensions

More terms from R. J. Mathar, Apr 22 2009

A159746 If an array is made of columns of -nacci sequences, fibo-, tribo- etc. all starting w. 1,1,2 etc, the NW to SE diagonals can be extended by computation. The above is diagonal 9. See A159741 for details.

Original entry on oeis.org

55, 274, 773, 1793, 3840, 7936, 16128, 32512, 65280, 130816, 261888, 524032, 1048320, 2096896, 4194048, 8388352, 16776960, 33554176, 67108608, 134217472, 268435200, 536870656, 1073741568, 2147483392, 4294967040, 8589934336, 17179868928, 34359738112
Offset: 1

Views

Author

Al Hakanson (hawkuu(AT)gmail.com), Apr 20 2009

Keywords

Programs

  • Mathematica
    LinearRecurrence[{3,-2},{55,274,773,1793,3840,7936},30] (* Harvey P. Dale, Aug 18 2022 *)

Formula

Interpolate a(n)=(4*n^3-30*n^2+92*n+657)/3 offset 0 & b(n)=(-4*n^3+24*n^2-65*n+840)/3 offset 0. Add 55 as a leader. Binomially transform. [From Al Hakanson (hawkuu(AT)gmail.com), Jun 08 2009]
a(n) = 2^(7+n)-256 for n>=5. - R. J. Mathar, Feb 04 2021

Extensions

a(7) and beyond by R. J. Mathar, Feb 04 2021

A159748 If an array is made of columns of -nacci sequences, fibo-, tribo- etc. all starting w. 1,1,2 etc, the NW to SE diagonals can be extended by computation. The above is diagonal 11. See A159741 for details.

Original entry on oeis.org

144, 927, 2872, 6930, 15109, 31489, 64256, 129792, 260864, 523008, 1047296, 2095872, 4193024, 8387328, 16775936, 33553152, 67107584, 134216448, 268434176, 536869632, 1073740544, 2147482368, 4294966016, 8589933312, 17179867904
Offset: 1

Views

Author

Al Hakanson (hawkuu(AT)gmail.com), Apr 20 2009

Keywords

Crossrefs

Cf. A159741 .

Programs

  • Maple
    T := proc(n,m) option remember ; if n < 0 then 0; elif n <= 1 then 1; elif n = 2 then 2; else add(procname(n-i,m),i=1..m) ; fi: end: A159748 := proc(n) T(n+10,n+1) ; end: seq(A159748(n),n=1..40) ; # R. J. Mathar, Apr 22 2009

Formula

a(n) = 3*a(n-1) - 2*a(n-2), n > 8. - R. J. Mathar, Apr 22 2009
Interpolate a(n) = (4*n^5 - 60*n^4 + 415*n^3 - 1665*n^2 + 3826*n + 11745)/15 offset 0 and b(n) = -4*n^5 + 50*n^4 - 305*n^3 + 1127.5*n^2 - 2443.5 + 17430)/15 offset 0. Add the leading 144. Binomially transform. - Al Hakanson (hawkuu(AT)gmail.com), Jun 08 2009

Extensions

More terms from R. J. Mathar, Apr 22 2009

A159743 If an array is made of columns of -nacci sequences, fibo-, tribo- etc. all starting w. 1,1,2 etc, the NW to SE diagonals can be extended by computation. The above is diagonal 7. See A159741 for details.

Original entry on oeis.org

21, 81, 208, 464, 976, 2000, 4048
Offset: 1

Views

Author

Al Hakanson (hawkuu(AT)gmail.com), Apr 20 2009

Keywords

Formula

Interpolate a(n)=2*n+60 offset 0 & b(n)=-2*n+67 offset 0. Add 21 as a leader. Binomially transform. [From Al Hakanson (hawkuu(AT)gmail.com), Jun 08 2009]

A159744 If an array is made of columns of -nacci sequences, fibo-, tribo- etc. all starting w. 1,1,2 etc, the NW to SE diagonals can be extended by computation. The above is diagonal 8. See A159741 for details.

Original entry on oeis.org

34, 149, 401, 912, 1936, 3984, 8080
Offset: 1

Views

Author

Al Hakanson (hawkuu(AT)gmail.com), Apr 20 2009

Keywords

Formula

Interpolate a(n)=-2*n^2+9*n+115 offset 0 & b(n)=2*n^2-7*n+137 offset 0. Add 34 as a leader. Binomially transform. [From Al Hakanson (hawkuu(AT)gmail.com), Jun 08 2009]

A159747 If an array is made of columns of -nacci sequences, fibo-, tribo- etc. all starting w. 1,1,2 etc, the NW to SE diagonals can be extended by computation. The above is diagonal 10. See A159741 for details.

Original entry on oeis.org

89, 504, 1490, 3525, 7617, 15808, 32192, 64960, 130496, 261568, 523712, 1048000, 2096576, 4193728, 8388032, 16776640, 33553856, 67108288, 134217152, 268434880, 536870336, 1073741248, 2147483072, 4294966720, 8589934016, 17179868608, 34359737792, 68719476160, 137438952896
Offset: 1

Views

Author

Al Hakanson (hawkuu(AT)gmail.com), Apr 20 2009

Keywords

Formula

Interpolate a(n)=(-2*n^4+22*n^3-107.5*n^2+276.5*n+1245)/3 offset 0 & b(n)=(2*n^4-18*n^3+77.5*n^2-184.5*n+1713)/3 offset 0. Add a leading 89. Binomially transform. [From Al Hakanson (hawkuu(AT)gmail.com), Jun 08 2009]
a(n) = T(n+9,n+1) with T defined in A159741. a(n) = 2^(n+8)-576 for n>=6. - R. J. Mathar, Feb 04 2021

Extensions

a(8) and beyond by R. J. Mathar, Feb 04 2021

A173787 Triangle read by rows: T(n,k) = 2^n - 2^k, 0 <= k <= n.

Original entry on oeis.org

0, 1, 0, 3, 2, 0, 7, 6, 4, 0, 15, 14, 12, 8, 0, 31, 30, 28, 24, 16, 0, 63, 62, 60, 56, 48, 32, 0, 127, 126, 124, 120, 112, 96, 64, 0, 255, 254, 252, 248, 240, 224, 192, 128, 0, 511, 510, 508, 504, 496, 480, 448, 384, 256, 0, 1023, 1022, 1020, 1016, 1008, 992, 960, 896, 768, 512, 0
Offset: 0

Views

Author

Reinhard Zumkeller, Feb 28 2010

Keywords

Examples

			Triangle begins as:
   0;
   1,  0;
   3,  2,  0;
   7,  6,  4,  0;
  15, 14, 12,  8,  0;
  31, 30, 28, 24, 16, 0;
		

Programs

  • Magma
    [2^n -2^k: k in [0..n], n in [0..15]]; // G. C. Greubel, Jul 13 2021
    
  • Mathematica
    Table[2^n -2^k, {n,0,15}, {k,0,n}]//Flatten (* G. C. Greubel, Jul 13 2021 *)
  • Sage
    flatten([[2^n -2^k for k in (0..n)] for n in (0..15)]) # G. C. Greubel, Jul 13 2021

Formula

A000120(T(n,k)) = A025581(n,k).
Row sums give A000337.
Central terms give A020522.
T(2*n+1, n) = A006516(n+1).
T(2*n+3, n+2) = A059153(n).
T(n, k) = A140513(n,k) - A173786(n,k), 0 <= k <= n.
T(n, k) = A173786(n,k) - A059268(n+1,k+1), 0 < k <= n.
T(2*n, 2*k) = T(n,k) * A173786(n,k), 0 <= k <= n.
T(n, 0) = A000225(n).
T(n, 1) = A000918(n) for n>0.
T(n, 2) = A028399(n) for n>1.
T(n, 3) = A159741(n-3) for n>3.
T(n, 4) = A175164(n-4) for n>4.
T(n, 5) = A175165(n-5) for n>5.
T(n, 6) = A175166(n-6) for n>6.
T(n, n-4) = A110286(n-4) for n>3.
T(n, n-3) = A005009(n-3) for n>2.
T(n, n-2) = A007283(n-2) for n>1.
T(n, n-1) = A000079(n-1) for n>0.
T(n, n) = A000004(n).

A175161 a(n) = 8*(2^n + 1).

Original entry on oeis.org

16, 24, 40, 72, 136, 264, 520, 1032, 2056, 4104, 8200, 16392, 32776, 65544, 131080, 262152, 524296, 1048584, 2097160, 4194312, 8388616, 16777224, 33554440, 67108872, 134217736, 268435464, 536870920, 1073741832, 2147483656, 4294967304, 8589934600, 17179869192
Offset: 0

Views

Author

Reinhard Zumkeller, Feb 28 2010

Keywords

Crossrefs

Sequences of the form m*(2^n + 1): A000051 (m=1), A052548 (m=2), A140504 (m=4), A153973 (m=6), A231643 (m=5), this sequence (m=8), A175162 (m=16), A175163 (m=32).

Programs

  • Magma
    I:=[16,24]; [n le 2 select I[n] else 3*Self(n-1) - 2*Self(n-2): n in [1..41]]; // G. C. Greubel, Jul 08 2021
    
  • Mathematica
    8*(2^Range[0, 40] + 1) (* G. C. Greubel, Jul 08 2021 *)
    LinearRecurrence[{3,-2},{16,24},40] (* Harvey P. Dale, Feb 10 2022 *)
  • Sage
    [8*(2^n +1) for n in (0..40)] # G. C. Greubel, Jul 08 2021

Formula

a(n) = A173786(n+3, 3).
a(n) = A175166(2*n)/A159741(n) for n > 0.
a(n) = 3*a(n-1) -2*a(n-2) with a(0)=16, a(1)=24. - Vincenzo Librandi, Dec 28 2010
G.f.: 8*(2 - 3*x)/((1-x)*(1-2*x)). - Chai Wah Wu, Jun 20 2020
a(n) = 8 * A000051(n). - Alois P. Heinz, Jun 20 2020
E.g.f.: 8*(exp(2*x) + exp(x)). - G. C. Greubel, Jul 08 2021

A175164 a(n) = 16*(2^n - 1).

Original entry on oeis.org

0, 16, 48, 112, 240, 496, 1008, 2032, 4080, 8176, 16368, 32752, 65520, 131056, 262128, 524272, 1048560, 2097136, 4194288, 8388592, 16777200, 33554416, 67108848, 134217712, 268435440
Offset: 0

Views

Author

Reinhard Zumkeller, Feb 28 2010

Keywords

Crossrefs

Sequences of the form m*(2^n - 1): A000225 (m=1), A000918 (m=2), A068156 (m=3), A028399 (m=4), A068293 (m=6), A159741 (m=8), this sequence (m=16), A175165 (m=32), A175166 (m=64).

Programs

  • Magma
    I:=[0,16]; [n le 2 select I[n] else 3*Self(n-1) - 2*Self(n-2): n in [1..41]]; // G. C. Greubel, Jul 08 2021
    
  • Mathematica
    16*(2^Range[0,40] - 1) (* G. C. Greubel, Jul 08 2021 *)
  • Python
    def A175164(n): return (1<Chai Wah Wu, Jun 27 2023
  • Sage
    [16*(2^n -1) for n in (0..40)] # G. C. Greubel, Jul 08 2021
    

Formula

a(n) = 2^(n+4) - 16.
a(n) = A173787(n+4, 4).
a(2*n) = A140504(n+2)*A028399(n).
a(n) = 3*a(n-1) - 2*a(n-2), a(0)=0, a(1)=16. - Vincenzo Librandi, Dec 28 2010
From G. C. Greubel, Jul 08 2021: (Start)
G.f.: 16*x/((1-x)*(1-2*x)).
E.g.f.: 16*(exp(2*x) - exp(x)). (End)

A175166 a(n) = 64*(2^n - 1).

Original entry on oeis.org

0, 64, 192, 448, 960, 1984, 4032, 8128, 16320, 32704, 65472, 131008, 262080, 524224, 1048512, 2097088, 4194240, 8388544, 16777152, 33554368, 67108800, 134217664, 268435392, 536870848, 1073741760
Offset: 0

Views

Author

Reinhard Zumkeller, Feb 28 2010

Keywords

Crossrefs

Sequences of the form m*(2^n - 1): A000225 (m=1), A000918 (m=2), A068156 (m=3), A028399 (m=4), A068293 (m=6), A159741 (m=8), A175164 (m=16), A175165 (m=32), this sequence (m=64).

Programs

  • Magma
    I:=[0,64]; [n le 2 select I[n] else 3*Self(n-1) - 2*Self(n-2): n in [1..41]]; // G. C. Greubel, Jul 08 2021
    
  • Mathematica
    LinearRecurrence[{3,-2},{0,64},30] (* Harvey P. Dale, Apr 08 2015 *)
  • Python
    def A175166(n): return (1<Chai Wah Wu, Jun 27 2023
  • Sage
    [64*(2^n -1) for n in (0..40)] # G. C. Greubel, Jul 08 2021
    

Formula

a(n) = 2^(n+6) - 64.
a(n) = A173787(n+6, 6).
a(2*n) = A175161(n)*A159741(n) for n > 0.
a(n) = 3*a(n-1) - 2*a(n-2), a(0)=0, a(1)=64. - Vincenzo Librandi, Dec 28 2010
From G. C. Greubel, Jul 08 2021: (Start)
G.f.: 64*x/((1-x)*(1-2*x)).
E.g.f.: 64*(exp(2*x) - exp(x)). (End)
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