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.

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A068908 Number of partitions of n modulo 5.

Original entry on oeis.org

1, 1, 2, 3, 0, 2, 1, 0, 2, 0, 2, 1, 2, 1, 0, 1, 1, 2, 0, 0, 2, 2, 2, 0, 0, 3, 1, 0, 3, 0, 4, 2, 4, 3, 0, 3, 2, 2, 0, 0, 3, 3, 4, 1, 0, 4, 3, 4, 3, 0, 1, 3, 4, 1, 0, 1, 3, 4, 0, 0, 2, 0, 1, 4, 0, 3, 0, 4, 0, 0, 3, 0, 3, 4, 0, 4, 1, 3, 4, 0, 1, 2, 0, 4, 0, 2, 2, 3, 4, 0, 3, 4, 2, 2, 0, 4, 4, 0, 1, 0, 2, 1, 4, 0, 0
Offset: 0

Views

Author

Henry Bottomley, Mar 05 2002

Keywords

Comments

Of the partitions of numbers from 1 to 100000: 36256 are 0, 15758 are 1, 16133 are 2, 16028 are 3 and 15825 are 4 modulo 5, largely because the number of partitions of 5m+4 is always a multiple of 5.

Crossrefs

Programs

  • Mathematica
    Mod[PartitionsP[Range[0,110]],5] (* Harvey P. Dale, Dec 20 2023 *)
  • PARI
    a(n) = numbpart(n) % 5; \\ Michel Marcus, Jul 14 2022

Formula

a(n) = A010874(A000041(n)) = A068906(5, n).
a(n) = Pm(n,1) with Pm(n,k) = if kReinhard Zumkeller, Jun 09 2009]

A130489 a(n) = Sum_{k=0..n} (k mod 11) (Partial sums of A010880).

Original entry on oeis.org

0, 1, 3, 6, 10, 15, 21, 28, 36, 45, 55, 55, 56, 58, 61, 65, 70, 76, 83, 91, 100, 110, 110, 111, 113, 116, 120, 125, 131, 138, 146, 155, 165, 165, 166, 168, 171, 175, 180, 186, 193, 201, 210, 220, 220, 221, 223, 226, 230, 235, 241, 248, 256, 265, 275, 275, 276
Offset: 0

Views

Author

Hieronymus Fischer, May 31 2007

Keywords

Comments

Let A be the Hessenberg n X n matrix defined by A[1,j] = j mod 11, A[i,i]:=1, A[i,i-1]=-1. Then, for n >= 1, a(n)=det(A). - Milan Janjic, Jan 24 2010

Crossrefs

Programs

  • GAP
    a:=[0,1,3,6,10,15,21,28,36,45, 55,55];; for n in [13..61] do a[n]:=a[n-1]+a[n-11]-a[n-12]; od; a; # G. C. Greubel, Aug 31 2019
  • Magma
    I:=[0,1,3,6,10,15,21,28,36,45,55,55]; [n le 12 select I[n] else Self(n-1) + Self(n-11) - Self(n-12): n in [1..61]]; // G. C. Greubel, Aug 31 2019
    
  • Maple
    seq(coeff(series(x*(1-11*x^10+10*x^11)/((1-x^11)*(1-x)^3), x, n+1), x, n), n = 0 .. 60); # G. C. Greubel, Aug 31 2019
  • Mathematica
    LinearRecurrence[{1,0,0,0,0,0,0,0,0,0,1,-1}, {0,1,3,6,10,15,21,28,36,45, 55,55}, 60] (* G. C. Greubel, Aug 31 2019 *)
    Accumulate[PadRight[{},80,Range[0,10]]] (* Harvey P. Dale, Jul 21 2021 *)
  • PARI
    a(n) = sum(k=0, n, k % 11); \\ Michel Marcus, Apr 28 2018
    
  • Sage
    def A130489_list(prec):
        P. = PowerSeriesRing(ZZ, prec)
        return P(x*(1-11*x^10+10*x^11)/((1-x^11)*(1-x)^3)).list()
    A130489_list(60) # G. C. Greubel, Aug 31 2019
    

Formula

a(n) = 55*floor(n/11) + A010880(n)*(A010880(n) + 1)/2.
G.f.: (Sum_{k=1..10} k*x^k)/((1-x^11)*(1-x)).
G.f.: x*(1 - 11*x^10 + 10*x^11)/((1-x^11)*(1-x)^3).

A379115 a(n) = A328845(n) mod 5, where A328845 is the first Fibonacci based variant of arithmetic derivative.

Original entry on oeis.org

0, 0, 1, 2, 4, 0, 2, 3, 2, 2, 0, 4, 0, 3, 3, 0, 2, 2, 3, 1, 0, 3, 4, 2, 2, 0, 4, 4, 0, 4, 0, 4, 0, 4, 1, 0, 4, 2, 1, 0, 0, 1, 2, 2, 0, 0, 2, 3, 3, 2, 0, 0, 4, 3, 0, 0, 3, 1, 2, 1, 0, 1, 4, 1, 2, 0, 1, 3, 1, 2, 0, 4, 4, 3, 1, 0, 0, 1, 4, 1, 0, 1, 3, 2, 1, 0, 2, 0, 4, 4, 0, 0, 0, 4, 3, 0, 4, 2, 3, 3, 0, 1, 1, 2, 0, 0
Offset: 0

Views

Author

Antti Karttunen, Dec 15 2024

Keywords

Crossrefs

Cf. A010874, A328845, A374125, A374205, A379116 (positions of 0's), A379117 (their characteristic function).

Programs

  • Mathematica
    A379115[n_] := If[n <= 1, 0, Mod[n*Total[MapApply[#2*Fibonacci[#]/# &, FactorInteger[n]]], 5]];
    Array[A379115, 100, 0] (* Paolo Xausa, Dec 16 2024 *)
  • PARI
    A379115(n) = if(n<=1, 0, my(f=factor(n)); (n*sum(i=1, #f~, f[i, 2]*fibonacci(f[i,1])/f[i, 1]))%5);

Formula

a(n) = A010874(A328845(n)) = A010874(A374125(n)).

A010885 Period 6: repeat [1, 2, 3, 4, 5, 6].

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 5, 6, 1, 2, 3
Offset: 0

Views

Author

Keywords

Comments

Partial sums are given by A130484(n)+n+1. - Hieronymus Fischer, Jun 08 2007
41152/333333 = 0.123456123456123456... [Eric Desbiaux, Nov 03 2008]

Crossrefs

Cf. A177158 (decimal expansion of (103+2*sqrt(4171))/162). [From Klaus Brockhaus, May 03 2010]

Programs

Formula

a(n) = 1 + (n mod 6). - Paolo P. Lava, Nov 21 2006
a(n) = A010875(n)+1. G.f.: g(x)=(Sum_{0<=k<6} (k+1)*x^k)/(1-x^6). Also g(x)=(6*x^7-7*x^6+1)/((1-x^6)*(1-x)^2). - Hieronymus Fischer, Jun 08 2007
From Wesley Ivan Hurt, Jun 17 2016: (Start)
G.f.: (1+2*x+3*x^2+4*x^3+5*x^4+6*x^5)/(1-x^6).
a(n) = (21-3*cos(n*Pi)-4*sqrt(3)*cos((1-4*n)*Pi/6)-12*sin((1+2*n)*Pi/6))/6.
a(n) = a(n-6) for n>5. (End)

A010889 Simple periodic sequence: repeat 1,2,3,4,5,6,7,8,9,10.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1
Offset: 0

Views

Author

Keywords

Comments

Partial sums are given by A130488(n)+n+1. - Hieronymus Fischer, Jun 08 2007
Continued fraction expansion of (232405+sqrt(71216963807))/348378. [From Klaus Brockhaus, May 15 2010]

Crossrefs

Cf. A177933 (decimal expansion of (232405+sqrt(71216963807))/348378). [From Klaus Brockhaus, May 15 2010]

Programs

  • Mathematica
    PadRight[{},120,Range[10]] (* Harvey P. Dale, Feb 22 2015 *)
  • Python
    def a(n): return n % 10 + 1 # Paul Muljadi, Aug 06 2024

Formula

a(n) = 1 + (n mod 10) - Paolo P. Lava, Nov 21 2006
From Hieronymus Fischer, Jun 08 2007: (Start)
a(n) = A010879(n)+1.
G.f.: (Sum_{k=0..9} (k+1)*x^k)/(1-x^10).
G.f.: (10x^11-11x^10+1)/((1-x^10)(1-x)^2). (End)

Extensions

More terms from Klaus Brockhaus, May 15 2010

A053840 (Sum of digits of n written in base 5) modulo 5.

Original entry on oeis.org

0, 1, 2, 3, 4, 1, 2, 3, 4, 0, 2, 3, 4, 0, 1, 3, 4, 0, 1, 2, 4, 0, 1, 2, 3, 1, 2, 3, 4, 0, 2, 3, 4, 0, 1, 3, 4, 0, 1, 2, 4, 0, 1, 2, 3, 0, 1, 2, 3, 4, 2, 3, 4, 0, 1, 3, 4, 0, 1, 2, 4, 0, 1, 2, 3, 0, 1, 2, 3, 4, 1, 2, 3, 4, 0, 3, 4, 0, 1, 2, 4, 0, 1, 2, 3, 0, 1, 2, 3, 4, 1, 2, 3, 4, 0, 2, 3, 4, 0, 1, 4, 0, 1, 2, 3
Offset: 0

Views

Author

Henry Bottomley, Mar 28 2000

Keywords

Comments

a(n) is the fourth row of the array in A141803. - Andrey Zabolotskiy, May 16 2016

Crossrefs

Programs

  • Mathematica
    Mod[Total@ IntegerDigits[#, 5], 5] & /@ Range[0, 120] (* Michael De Vlieger, May 17 2016 *)
  • PARI
    a(n) = vecsum(digits(n,5)) % 5; \\ Michel Marcus, May 16 2016

Formula

a(n) = A010874(A053824(n)). - Andrey Zabolotskiy, May 18 2016

A070471 a(n) = n^3 mod 5.

Original entry on oeis.org

0, 1, 3, 2, 4, 0, 1, 3, 2, 4, 0, 1, 3, 2, 4, 0, 1, 3, 2, 4, 0, 1, 3, 2, 4, 0, 1, 3, 2, 4, 0, 1, 3, 2, 4, 0, 1, 3, 2, 4, 0, 1, 3, 2, 4, 0, 1, 3, 2, 4, 0, 1, 3, 2, 4, 0, 1, 3, 2, 4, 0, 1, 3, 2, 4, 0, 1, 3, 2, 4, 0, 1, 3, 2, 4, 0, 1, 3, 2, 4, 0, 1, 3, 2, 4, 0, 1, 3, 2, 4, 0, 1, 3, 2, 4, 0, 1, 3, 2, 4, 0
Offset: 0

Views

Author

N. J. A. Sloane, May 12 2002

Keywords

Comments

Decimal expansion of 1324/99999. - Vincenzo Librandi, Dec 09 2010

Crossrefs

Cf. A010874.

Programs

  • Mathematica
    CoefficientList[Series[-x (1 + 3 x + 2 x^2 + 4 x^3)/((x - 1) (1 + x + x^2 + x^3 + x^4)), {x, 0, 100}], x] (* Vincenzo Librandi, May 21 2014 *)
    PowerMod[Range[0, 100], 3, 5] (* G. C. Greubel, Mar 26 2016 *)
    Table[If[Mod[n, 5] == 0, 0, ModularInverse[n, 5]], {n, 0, 100}] (* Jean-François Alcover, May 03 2017 *)
  • PARI
    my(x='x+O('x^99)); concat(0, Vec(-x*(1+3*x+2*x^2+4*x^3)/((x-1)*(1+x+x^2+x^3+x^4)))) \\ Altug Alkan, Mar 27 2016
    
  • PARI
    a(n) = lift(Mod(n, 5)^3); \\ Michel Marcus, Jun 03 2025
  • Sage
    [power_mod(n,3,5) for n in (0..101)] # Zerinvary Lajos, Oct 29 2009
    

Formula

a(n) = n^7 mod 5 since 7 == 3 (mod 5-1).
G.f.: -x*(1+3*x+2*x^2+4*x^3) / ( (x-1)*(1+x+x^2+x^3+x^4) ). - R. J. Mathar, Dec 10 2010
a(n) = a(n-5). - G. C. Greubel, Mar 26 2016
a(n) = 10 - Sum_{k=1..4} a(n-k) for n > 3. - Nicolas Bělohoubek, Jun 03 2025

A130490 a(n) = Sum_{k=0..n} (k mod 12) (Partial sums of A010881).

Original entry on oeis.org

0, 1, 3, 6, 10, 15, 21, 28, 36, 45, 55, 66, 66, 67, 69, 72, 76, 81, 87, 94, 102, 111, 121, 132, 132, 133, 135, 138, 142, 147, 153, 160, 168, 177, 187, 198, 198, 199, 201, 204, 208, 213, 219, 226, 234, 243, 253, 264, 264, 265, 267, 270, 274, 279, 285, 292, 300
Offset: 0

Views

Author

Hieronymus Fischer, May 31 2007

Keywords

Comments

Let A be the Hessenberg n X n matrix defined by: A[1,j] = j mod 12, A[i,i]:=1, A[i,i-1]=-1. Then, for n >= 1, a(n)=det(A). - Milan Janjic, Jan 24 2010

Crossrefs

Programs

  • GAP
    List([0..60], n-> Sum([0..n], k-> k mod 12 )); # G. C. Greubel, Sep 01 2019
  • Magma
    [&+[(k mod 12): k in [0..n]]: n in [0..60]]; // G. C. Greubel, Sep 01 2019
    
  • Maple
    seq(coeff(series(x*(1-12*x^11+11*x^12)/((1-x^12)*(1-x)^3), x, n+1), x, n), n = 0..60); # G. C. Greubel, Sep 01 2019
  • Mathematica
    Sum[Mod[k, 12], {k, 0, Range[0, 60]}] (* G. C. Greubel, Sep 01 2019 *)
    LinearRecurrence[{1,0,0,0,0,0,0,0,0,0,0,1,-1},{0,1,3,6,10,15,21,28,36,45,55,66,66},60] (* Harvey P. Dale, Jan 16 2024 *)
  • PARI
    a(n) = sum(k=0, n, k % 12); \\ Michel Marcus, Apr 29 2018
    
  • Sage
    [sum(k%12 for k in (0..n)) for n in (0..60)] # G. C. Greubel, Sep 01 2019
    

Formula

a(n) = 66*floor(n/12) + A010881(n)*(A010881(n) + 1)/2.
G.f.: (Sum_{k=1..11} k*x^k)/((1-x^12)*(1-x)).
G.f.: x*(1 - 12*x^11 + 11*x^12)/((1-x^12)*(1-x)^3).

A379225 a(n) = A113177(n) mod 5, where A113177 is fully additive with a(p) = Fibonacci(p).

Original entry on oeis.org

0, 1, 2, 2, 0, 3, 3, 3, 4, 1, 4, 4, 3, 4, 2, 4, 2, 0, 1, 2, 0, 0, 2, 0, 0, 4, 1, 0, 4, 3, 4, 0, 1, 3, 3, 1, 2, 2, 0, 3, 1, 1, 2, 1, 4, 3, 3, 1, 1, 1, 4, 0, 3, 2, 4, 1, 3, 0, 1, 4, 1, 0, 2, 1, 3, 2, 3, 4, 4, 4, 4, 2, 3, 3, 2, 3, 2, 1, 1, 4, 3, 2, 2, 2, 2, 3, 1, 2, 4, 0, 1, 4, 1, 4, 1, 2, 2, 2, 3, 2, 1, 0, 2, 1, 0
Offset: 1

Views

Author

Antti Karttunen, Dec 20 2024

Keywords

Crossrefs

Cf. also A379115.

Programs

  • PARI
    A113177(n) = if(n<=1, 0, my(f=factor(n)); sum(i=1, #f~, f[i, 2]*fibonacci(f[i, 1])));
    A379225(n) = (A113177(n)%5);

Formula

a(n) = A010874(A113177(n)) = A010874(A374124(n)).

A010884 Period 5: repeat [1,2,3,4,5].

Original entry on oeis.org

1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1
Offset: 0

Views

Author

Keywords

Comments

Partial sums are given by A130483(n)+n+1. - Hieronymus Fischer, Jun 08 2007
4115/33333 = 0.12345123451234512345... - Eric Desbiaux, Nov 03 2008

Crossrefs

Cf. A177038 (decimal expansion of (195+sqrt(65029))/314).

Programs

Formula

a(n) = 1 + (n mod 5). - Paolo P. Lava, Nov 21 2006
From Hieronymus Fischer, Jun 08 2007: (Start)
G.f.: (5*x^4+4*x^3+3*x^2+2*x+1)/(1-x^5) = (5*x^6-6*x^5+1)/((1-x^5)*(1-x)^2).
a(n) = A010874(n)+1. (End)
a(n) = a(n-5). - Wesley Ivan Hurt, Jan 15 2022
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