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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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

A068909 Number of partitions of n modulo 7.

Original entry on oeis.org

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

Views

Author

Henry Bottomley, Mar 05 2002

Keywords

Comments

Of the partitions of numbers from 1 to 100000: 27193 are 0, 12078 are 1, 12203 are 2, 12260 are 3, 12231 are 4, 12003 are 5 and 12032 are 6 modulo 7, largely because the number of partitions of 7m+5 is always a multiple of 7.

Crossrefs

Programs

  • Mathematica
    Table[Mod[PartitionsP[n],7],{n,0,110}] (* Harvey P. Dale, Feb 17 2018 *)
  • PARI
    a(n) = numbpart(n) % 7; \\ Michel Marcus, Jul 14 2022

Formula

a(n) = A010876(A000041(n)) = A068906(7, n).
a(n) = Pm(n,1) with Pm(n,k) = if kReinhard Zumkeller, Jun 09 2009]

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).

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

A053842 (Sum of digits of n written in base 7) modulo 7.

Original entry on oeis.org

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

Views

Author

Henry Bottomley, Mar 28 2000

Keywords

Comments

a(n) is the sixth row of the array in A141803. - Andrey Zabolotskiy, May 18 2016

Crossrefs

Programs

  • Mathematica
    Table[Mod[Plus @@ IntegerDigits[n, 7], 7], {n, 0, 50}] (* G. C. Greubel, Nov 02 2017 *)
  • PARI
    a(n) = vecsum(digits(n, 7)) % 7; \\ Michel Marcus, May 18 2016

Formula

a(n) = A010876(A053828(n)). - Andrey Zabolotskiy, May 18 2016

A130910 Sum {0<=k<=n, k mod 16} (Partial sums of A130909).

Original entry on oeis.org

0, 1, 3, 6, 10, 15, 21, 28, 36, 45, 55, 66, 78, 91, 105, 120, 120, 121, 123, 126, 130, 135, 141, 148, 156, 165, 175, 186, 198, 211, 225, 240, 240, 241, 243, 246, 250, 255, 261, 268, 276, 285, 295, 306, 318, 331, 345, 360, 360, 361, 363, 366, 370, 375, 381, 388
Offset: 0

Views

Author

Hieronymus Fischer, Jun 11 2007

Keywords

Crossrefs

Programs

  • Mathematica
    Accumulate[Mod[Range[0,60],16]] (* Harvey P. Dale, May 30 2020 *)

Formula

a(n)=120*floor(n/16)+A130909(n)*(A130909(n)+1)/2. - G.f.: g(x)=(sum{1<=k<16, k*x^k})/((1-x^16)(1-x)). Also: g(x)=x(15x^16-16x^15+1)/((1-x^16)(1-x)^3).
a(n) = +a(n-1) +a(n-16) -a(n-17). G.f. ( x*(1 +2*x +3*x^2 +4*x^3 +5*x^4 +6*x^5 +7*x^6 +8*x^7 +9*x^8 +10*x^9 +11*x^10 +12*x^11 +13*x^12 +14*x^13 +15*x^14) ) / ( (1+x) *(1+x^2) *(1+x^4) *(1+x^8) *(x-1)^2 ). - R. J. Mathar, Nov 05 2011

A272647 a(n) = A001517(n) mod 7.

Original entry on oeis.org

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

Views

Author

N. J. A. Sloane, May 09 2016

Keywords

Comments

Periodic with period length 7.

Crossrefs

Programs

  • Maple
    f:=proc(n) option remember; if n = 0 then 1 elif n=1 then 3 else f(n-2)+(4*n-2)*f(n-1); fi; end;
    [seq(f(n) mod 7, n=0..120)];
  • Mathematica
    PadRight[{},120,{1,3,5,4,5,3,1}] (* Harvey P. Dale, Jul 17 2020 *)
  • PARI
    Vec((1+3*x+5*x^2+4*x^3+5*x^4+3*x^5+x^6)/((1-x)*(1+x+x^2+x^3+x^4+x^5+x^6)) + O(x^50)) \\ Colin Barker, May 10 2016

Formula

G.f.: (1 + 3*x + 5*x^2 + 4*x^3 + 5*x^4 + 3*x^5 + x^6) / ((1 - x)*(1 + x + x^2 + x^3 + x^4 + x^5 + x^6)). - Colin Barker, May 10 2016
a(n) = (3*m^6 - 54*m^5 + 365*m^4 - 1140*m^3 + 1582*m^2 - 636*m + 60)/60, where m = n mod 7. - Luce ETIENNE, Oct 18 2018

A272648 a(n) = A002119(n) mod 7.

Original entry on oeis.org

1, 1, 0, 1, 0, 1, 1, 6, 6, 0, 6, 0, 6, 6, 1, 1, 0, 1, 0, 1, 1, 6, 6, 0, 6, 0, 6, 6, 1, 1, 0, 1, 0, 1, 1, 6, 6, 0, 6, 0, 6, 6, 1, 1, 0, 1, 0, 1, 1, 6, 6, 0, 6, 0, 6, 6, 1, 1, 0, 1, 0, 1, 1, 6, 6, 0, 6, 0, 6, 6, 1, 1, 0, 1, 0, 1, 1, 6, 6, 0, 6
Offset: 0

Views

Author

N. J. A. Sloane, May 09 2016

Keywords

Comments

Periodic with period 14.

Crossrefs

Programs

  • GAP
    b:=[1,-1];; for n in [3..95] do b[n]:=-2*(2*n-3)*b[n-1]+b[n-2]; od; a:=List(b,AbsInt) mod 7; # Muniru A Asiru, Sep 20 2018
  • Maple
    f:=proc(n) option remember; if n = 0 then 1 elif n=1 then 1 else f(n-2)+(4*n-2)*f(n-1); fi; end;
    [seq(f(n) mod 7, n=0..120)];
  • Mathematica
    PadRight[{},120,{1,1,0,1,0,1,1,6,6,0,6,0,6,6}] (* Harvey P. Dale, Jun 07 2016 *)
  • PARI
    Vec((1+x+x^3+x^5+x^6)*(1+6*x^7)/((1-x)*(1+x)*(1-x+x^2-x^3+x^4-x^5+x^6)*(1+x+x^2+x^3+x^4+x^5+x^6)) + O(x^50)) \\ Colin Barker, May 10 2016
    

Formula

G.f.: (1+x+x^3+x^5+x^6)*(1+6*x^7) / ((1-x)*(1+x)*(1-x+x^2-x^3+x^4-x^5+x^6)*(1+x+x^2+x^3+x^4+x^5+x^6)). - Colin Barker, May 10 2016
a(n) = (-m^6+18*m^5-122*m^4+384*m^3-549*m^2+270*m+24)*(7-5*(-1)^floor(n/7))/48, where m = (n mod 7). - Luce ETIENNE, Sep 21 2018

A279316 Period 7: repeat [0, 1, 2, 3, 3, 2, 1].

Original entry on oeis.org

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

Views

Author

Wesley Ivan Hurt, Dec 09 2016

Keywords

Crossrefs

Cf. A279313.
Cf. A010876.

Programs

  • Magma
    &cat[[0, 1, 2, 3, 3, 2, 1]: n in [0..10]];
  • Maple
    a:=n->[0, 1, 2, 3, 3, 2, 1][(n mod 7)+1]: seq(a(n), n=0..300);
  • Mathematica
    CoefficientList[Series[x*(1 + 2*x + 3*x^2 + 3*x^3 + 2*x^4 + x^5)/(1 - x^7), {x, 0, 100}], x]
    PadRight[{}, 120, {0, 1, 2, 3, 3, 2, 1}] (* Vincenzo Librandi, Dec 10 2016 *)

Formula

G.f.: x*(1 + 2*x + 3*x^2 + 3*x^3 + 2*x^4 + x^5)/(1 - x^7).
a(n) = (1/2) * Sum_{i=1..2n} (-1)^floor((i-1)/7).
a(n) = a(n-7) for n > 6.
a(n) = A279313(2n)/2.
a(n) = -m*(m^5 - 21*m^4 + 160*m^3 - 525*m^2 + 739*m - 714)/360 where m = n mod 7. - Luce ETIENNE, Nov 18 2018

A010886 Period 7: repeat [1, 2, 3, 4, 5, 6, 7].

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 1, 2, 3, 4, 5, 6, 7, 1, 2, 3, 4, 5, 6, 7, 1, 2, 3, 4, 5, 6, 7, 1, 2, 3, 4, 5, 6, 7, 1, 2, 3, 4, 5, 6, 7, 1, 2, 3, 4, 5, 6, 7, 1, 2, 3, 4, 5, 6, 7, 1, 2, 3, 4, 5, 6, 7, 1, 2, 3, 4, 5, 6, 7, 1, 2, 3, 4, 5, 6, 7, 1, 2, 3, 4
Offset: 0

Views

Author

Keywords

Comments

Partial sums are given by A130485(n)+n+1. - Hieronymus Fischer, Jun 08 2007
Decimal expansion of 1234567/9999999 = 0.123456712345671234567... - Eric Desbiaux, Nov 03 2008

Crossrefs

Cf. A177160 (decimal expansion of (4502+sqrt(29964677))/6961).

Programs

Formula

a(n) = 1 + (n mod 7). - Paolo P. Lava, Nov 21 2006
a(n) = A010876(n) + 1. G.f.: (Sum_{k=0..6} (k+1)*x^k)/(1-x^7). Also (7*x^8-8*x^7+1)/((1-x^7)*(1-x)^2). - Hieronymus Fischer, Jun 08 2007
From Wesley Ivan Hurt, Jul 18 2016: (Start)
a(n) = a(n-7) for n>6.
a(n) = 1 - 6*floor(n/7) + Sum_{k=1..6} floor((n + k)/7). (End)
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