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.

A104249 a(n) = (3*n^2 + n + 2)/2.

Original entry on oeis.org

1, 3, 8, 16, 27, 41, 58, 78, 101, 127, 156, 188, 223, 261, 302, 346, 393, 443, 496, 552, 611, 673, 738, 806, 877, 951, 1028, 1108, 1191, 1277, 1366, 1458, 1553, 1651, 1752, 1856, 1963, 2073, 2186, 2302, 2421, 2543, 2668, 2796, 2927, 3061, 3198, 3338, 3481
Offset: 0

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Author

Thomas Wieder, Feb 26 2005

Keywords

Comments

Second differences are all 3.
Related to the sequence of odd numbers A005408 since for these numbers the first differences are all 2.
Column 2 of A114202. - Paul Barry, Nov 17 2005
Equals third row of A167560 divided by 2. - Johannes W. Meijer, Nov 12 2009
A242357(a(n)) = n + 1. - Reinhard Zumkeller, May 11 2014
Also, this sequence is related to A011379, for n>0, by A011379(n) = n*a(n) - Sum_{i=0..n-1} a(i). - Bruno Berselli, Jul 08 2015
The number of Hamiltonian nonisomorphic unfoldings in an n-gonal Archimedean antiprism. See sequence A284647. - Rick Mabry, Apr 10 2021

Examples

			The sequence of first differences delta_a(n) = a(n+1) - a(n) is 2, 5, 8, 11, 14, 17, 20, 23, 26, ...
The sequence of second differences delta_delta_a(n) = a(n+2) - 2*a(n+1) + a(n) is: 3, 3, 3, 3, 3, 3, 3, ... E.g., 78 - 2*58 + 41 = 3.
		

Crossrefs

Counts special cases of A284647.

Programs

  • Haskell
    a104249 n = n*(3*n+1) `div` 2 + 1 -- Reinhard Zumkeller, May 11 2014
    
  • Magma
    [(3*n^2+n+2)/2: n in [0..50]]; // Vincenzo Librandi, May 09 2011
    
  • Maple
    a := proc (n) local i, u; option remember; u[0] := 1; u[1] := 3; u[2] := 8; for i from 3 to n do u[i] := -(4*u[i-3]-8*u[i-2]-2*u[i-1]+(-2*u[i-3]+2*u[i-2]-u[i-1])*i)/i end do; [seq(u[i],i = 0 .. n)] end proc;
  • Mathematica
    A104249[n_] := (3*n^2 + n + 2)/2; Table[A104249[n], {n,0,100}] (* Vladimir Joseph Stephan Orlovsky, Jul 22 2011 *)
    LinearRecurrence[{3,-3,1},{1,3,8},70] (* Harvey P. Dale, Jul 21 2023 *)
  • PARI
    a(n)=n*(3*n+1)/2+1 \\ Charles R Greathouse IV, Oct 07 2015

Formula

G.f.: (1 + 2*x^2)/(1 - x)^3.
Recurrence: (n+3)*u(n+3) + (-5-n)*u(n+2)*(-2+2*n)*u(n+1) + (-2-2*n)*u(n) = 0 for n >= 0 with u(0) = 1, u(1) = 3, and u(2) = 8.
From Paul Barry, Nov 17 2005: (Start)
a(0) = 1, a(n) = a(n-1) + 3*n - 1 for n > 0;
a(n) = Sum_{k=0..n} C(n, k)*C(2, k)*J(k+1), where J(n) = A001045(n). (End)
Binomial transform of [1, 2, 3, 0, 0, 0, ...]. - Gary W. Adamson, Apr 23 2008
E.g.f.: exp(x)*(2 + 4*x + 3*x^2)/2. - Stefano Spezia, Apr 10 2021

A064349 Generating function: 1/((1-x)*(1-x^2)^2*(1-x^3)^3*(1-x^4)^4).

Original entry on oeis.org

1, 1, 3, 6, 13, 19, 37, 58, 97, 143, 227, 328, 492, 688, 992, 1364, 1903, 2551, 3473, 4586, 6097, 7911, 10333, 13226, 16988, 21454, 27172, 33938, 42437, 52423, 64833, 79354, 97130, 117824, 142930, 172018, 206925, 247179, 295105, 350154, 415124
Offset: 0

Views

Author

Henry Bottomley, Sep 17 2001

Keywords

Comments

Number of partitions of n into parts 1 (of one kind), 2 (of two kinds), 3 (of three kinds), and 4 (of 4 kinds). [Joerg Arndt, Jul 11 2013]

Crossrefs

The sequence of sequences A000007, A000012, A008805, A002597, A064349, etc. approaches A000219.
Essentially the same as A002598.
Cf. A002598.

Programs

  • PARI
    a(n) = floor( ([13, 28, -44][n%3+1]+(9/2)*(n\3+2)*((n+1)%3-1)) * (n\3+1)/729 - (n\2+1)*(-1)^(n\2) * (3*[-8, 11]+(n\2+2)*(2*[-1, 3]+(n\2+3)*(1/3)*[0, 1]))[n%2+1]/512 + (2*n^9 +270*n^8 +15600*n^7 +504000*n^6 +9977730*n^5 +124629750*n^4 +973069200*n^3 +4521339000*n^2 +11137512613*n +16461579435 +5103*(n+15)*(2*n^4 +120*n^3 +2440*n^2 +19200*n +48213)*(-1)^n) / 20065812480 ) \\ Tani Akinari, Jul 12 2013
    
  • PARI
    Vec(1/((1-x)*(1-x^2)^2*(1-x^3)^3*(1-x^4)^4)+O(x^66)) \\ Joerg Arndt, Jul 11 2013

A002598 A generalized partition function.

Original entry on oeis.org

1, 6, 9, 13, 19, 37, 58, 97, 143, 227, 328, 492, 688, 992, 1364, 1903, 2551, 3473, 4586, 6097, 7911, 10333, 13226, 16988, 21454, 27172, 33938, 42437, 52423, 64833, 79354, 97130, 117824, 142930, 172018, 206925, 247179, 295105, 350154, 415124, 489414, 576540
Offset: 1

Views

Author

Keywords

References

  • Hansraj Gupta, A generalization of the partition function. Proc. Nat. Inst. Sci. India 17, (1951), 231-238.
  • N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Essentially the same as A064349.

Programs

  • Mathematica
    CoefficientList[Series[(3 x^32 - 9 x^30 - 10 x^29 - 2 x^28 + 29 x^27 + 43 x^26 + 9 x^25 - 54 x^24 - 107 x^23 - 49 x^22 + 76 x^21 + 162 x^20 + 125 x^19 - 53 x^18 - 189 x^17 - 172 x^16 - 11 x^15 + 157 x^14 + 166 x^13 + 50 x^12 - 81 x^11 - 119 x^10 - 49 x^9 + 30 x^8 + 55 x^7 + 29 x^6 - 8 x^5 - 18 x^4 - 9 x^3 + x^2 + 5 x + 1)/((x - 1)^10 (x + 1)^6 (x^2 + 1)^4 (x^2 + x + 1)^3), {x, 0, 50}], x] (* Vincenzo Librandi, Oct 13 2013 *)

Formula

G.f.: x*(3*x^32 -9*x^30 -10*x^29 -2*x^28 +29*x^27 +43*x^26 +9*x^25 -54*x^24 -107*x^23 -49*x^22 +76*x^21 +162*x^20 +125*x^19 -53*x^18 -189*x^17 -172*x^16 -11*x^15 +157*x^14 +166*x^13 +50*x^12 -81*x^11 -119*x^10 -49*x^9 +30*x^8 +55*x^7 +29*x^6 -8*x^5 -18*x^4 -9*x^3 +x^2 +5*x +1)/((x -1)^10*(x +1)^6*(x^2 +1)^4*(x^2 +x +1)^3). [Colin Barker, Oct 02 2012]

Extensions

More terms from Vincenzo Librandi, Oct 13 2013

A002600 A generalized partition function.

Original entry on oeis.org

1, 10, 25, 37, 42, 48, 79, 145, 244, 415, 672, 1100, 1722, 2727, 4193, 6428, 9658, 14478, 21313, 31304, 45329, 65311, 93074, 132026, 185413, 259242, 359395, 495839, 679175, 926064, 1254360, 1691753, 2268267, 3028345, 4021954, 5320139, 7003154
Offset: 1

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Author

Keywords

References

  • Hansraj Gupta, A generalization of the partition function. Proc. Nat. Inst. Sci. India 17 (1951), 231-238.
  • N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Programs

  • Maple
    J:= m-> product((1-x^j)^(-j), j=1..m): a:= t-> coeff(series(J(min(6, t)), x, 1+max(6, t)), x, max(6, t)): seq(a(n), n=1..40); # Alois P. Heinz, Jul 20 2009
  • Mathematica
    J[m_] := Product[(1-x^j)^-j, {j, 1, m}]; a[t_] := SeriesCoefficient[J[Min[6, t]], {x, 0, Max[6, t]}]; Table[a[n], {n, 1, 40}] (* Jean-François Alcover, Mar 13 2014, after Alois P. Heinz *)

Extensions

More terms from Alois P. Heinz, Jul 20 2009

A002599 A generalized partition function.

Original entry on oeis.org

1, 6, 15, 19, 24, 42, 73, 127, 208, 337, 528, 827, 1263, 1902, 2819, 4133, 5986, 8578, 12146, 17057, 23711, 32708, 44726, 60713, 81800, 109468, 145526, 192288, 252521, 329792, 428316, 553478, 711596, 910563, 1159790, 1470798, 1857286, 2335838
Offset: 1

Views

Author

Keywords

References

  • Hansraj Gupta, A generalization of the partition function. Proc. Nat. Inst. Sci. India 17 (1951), 231-238.
  • N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Programs

  • Maple
    J:= m-> product((1-x^j)^(-j), j=1..m): a:= t-> coeff(series(J(min(5, t)), x, 1+max(5, t)), x, max(5, t)): seq(a(n), n=1..40); # Alois P. Heinz, Jul 20 2009
  • Mathematica
    J[m_] := Product[(1-x^j)^-j, {j, 1, m}]; a[t_] := SeriesCoefficient[J[Min[5, t]], {x, 0, Max[5, t]}]; Table[a[n], {n, 1, 40}] (* Jean-François Alcover, Mar 13 2014, after Alois P. Heinz *)

Extensions

More terms from Alois P. Heinz, Jul 20 2009

A002601 A generalized partition function.

Original entry on oeis.org

1, 10, 34, 58, 73, 79, 86, 152, 265, 457, 763, 1268, 2058, 3308, 5236, 8220, 12731, 19546, 29685, 44702, 66714, 98806, 145154, 211756, 306667, 441249, 630771, 896344, 1266146, 1778692, 2485086, 3454206, 4777165, 6575350, 9008159
Offset: 1

Views

Author

Keywords

References

  • Hansraj Gupta, A generalization of the partition function. Proc. Nat. Inst. Sci. India 17 (1951), 231-238.
  • N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Programs

  • Maple
    J:= m-> product((1-x^j)^(-j), j=1..m): a:= t-> coeff(series(J(min(7, t)), x, 1+max(7, t)), x, max(7, t)): seq(a(n), n=1..40); # Alois P. Heinz, Jul 20 2009
  • Mathematica
    J[m_] := Product [(1-x^j)^-j, {j, 1, m}]; a[t_] := SeriesCoefficient[J[Min[7, t]], {x, 0, Max[7, t]}]; Table[a[n], {n, 1, 40}] (* Jean-François Alcover, Mar 17 2014, after Alois P. Heinz *)

Extensions

More terms from Alois P. Heinz, Jul 20 2009

A002602 A generalized partition function.

Original entry on oeis.org

1, 15, 51, 97, 127, 145, 152, 160, 273, 481, 811, 1372, 2250, 3692, 5924, 9472, 14887, 23310, 36005, 55314, 84042, 126998, 190138, 283108, 418175, 614429, 896439, 1301168, 1876826, 2693988, 3845134, 5462744, 7720947, 10864828, 15216527
Offset: 1

Views

Author

Keywords

References

  • Hansraj Gupta, A generalization of the partition function. Proc. Nat. Inst. Sci. India 17 (1951), 231-238.
  • N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Programs

  • Maple
    J:= m-> product((1-x^j)^(-j), j=1..m): a:= t-> coeff(series(J(min(8, t)), x, 1+max(8, t)), x, max(8, t)): seq(a(n), n=1..40); # Alois P. Heinz, Jul 20 2009
  • Mathematica
    J[m_] := Product[(1-x^j)^-j, {j, 1, m}]; a[t_] := SeriesCoefficient[J[Min[8, t]], {x, 0, Max[8, t]}]; Table[ a[n], {n, 1, 40}] (* Jean-François Alcover, Mar 17 2014, after Alois P. Heinz *)

Extensions

More terms from Alois P. Heinz, Jul 20 2009

A002603 A generalized partition function.

Original entry on oeis.org

1, 15, 73, 143, 208, 244, 265, 273, 282, 490, 838, 1426, 2367, 3908, 6356, 10246, 16327, 25812, 40379, 62748, 96660, 147833, 224446, 338584, 507293, 755612, 1118679, 1647023, 2411642, 3513096, 5091511, 7344086, 10543419, 15068833, 21442703, 30385111, 42880601
Offset: 1

Views

Author

Keywords

References

  • Hansraj Gupta, A generalization of the partition function. Proc. Nat. Inst. Sci. India 17 (1951), 231-238.
  • N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Programs

  • Maple
    J:= m-> product((1-x^j)^(-j), j=1..m): a:= t-> coeff(series(J(min(9, t)), x, 1+max(9, t)), x, max(9, t)): seq(a(n), n=1..40); # Alois P. Heinz, Jul 20 2009
  • Mathematica
    J[m_] := Product[(1-x^j)^-j, {j, 1, m}]; a[t_] := SeriesCoefficient[J[Min[9, t]], {x, 0, Max[9, t]}]; Table[ a[n], {n, 1, 40}] (* Jean-François Alcover, Mar 17 2014, after Alois P. Heinz *)

Extensions

More terms from Alois P. Heinz, Jul 20 2009
Showing 1-8 of 8 results.