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 1-7 of 7 results.

A059819 Expansion of series related to Liouville's Last Theorem: g.f. Sum_{t>0} (-1)^(t+1) *x^(t*(t+1)/2) / ( (1-x^t)^2 *Product_{i=1..t} (1-x^i) ).

Original entry on oeis.org

0, 1, 3, 5, 9, 11, 18, 19, 28, 30, 40, 39, 57, 51, 68, 68, 86, 77, 107, 91, 123, 114, 138, 121, 172, 140, 178, 166, 205, 171, 240, 189, 251, 224, 266, 230, 322, 245, 314, 286, 356, 283, 396, 303, 403, 361, 416, 343, 497, 368, 479, 424, 515, 407
Offset: 0

Views

Author

N. J. A. Sloane, Feb 24 2001

Keywords

Crossrefs

Cf. A000005 (k=1), here (k=2), A059820 (k=3), ..., A059825 (k=8).

Programs

  • Maple
    Mk := proc(k) -1*add( (-1)^n*q^(n*(n+1)/2)/(1-q^n)^k/mul(1-q^i,i=1..n), n=1..101): end; # with k=2

Formula

a(n) = (sigma(n)+tau(n)+Sum_{k=0..n} tau(k)*tau(n-k))/2.
G.f.: (F(x)+G(x)^2)/2, where F(x) = Sum_{k>0} (k+1)*x^k/(1-x^k) and G(x) = Sum_{k>0} x^k/(1-x^k). - Vladeta Jovovic, Feb 12 2004

A059820 Expansion of series related to Liouville's Last Theorem: g.f. Sum_{t>0} (-1)^(t+1) *x^(t*(t+1)/2) / ( (1-x^t)^3 *Product_{i=1..t} (1-x^i) ).

Original entry on oeis.org

0, 1, 4, 9, 19, 30, 52, 70, 107, 136, 191, 226, 314, 352, 463, 523, 664, 717, 919, 964, 1205, 1282, 1546, 1603, 1992, 2009, 2414, 2504, 2958, 2974, 3606, 3553, 4223, 4273, 4936, 4912, 5885, 5685, 6634, 6654, 7664, 7454, 8822, 8454, 9845
Offset: 0

Views

Author

N. J. A. Sloane, Feb 24 2001

Keywords

Crossrefs

Cf. A000005 (k=1), A059819 (k=2), A059820 (k=3), A059821(k=4), A059822 (k=5), A059823 (k=6), A059824 (k=7), A059825 (k=8).
Cf. A000203, A001157, A055507, A191829 (Andrews's D_{0,0,0}(n)), A191831 (Andrews's D_{0,1}(n)).

Programs

  • Maple
    Mk := proc(k) -1*add( (-1)^n*q^(n*(n+1)/2)/(1-q^n)^k/mul(1-q^i,i=1..n), n=1..101): end; # with k=3
  • PARI
    D(x, y, n) = sum(k=1, n-1, sigma(k, x)*sigma(n-k, y));
    D000(n) = sum(k=1, n-1, sigma(k, 0)*D(0, 0, n-k));
    a(n) = if(n==0, 0, (3*D(0, 0, n)+3*D(0, 1, n)+D000(n)+2*sigma(n, 0)+3*sigma(n)+sigma(n, 2))/6); \\ Seiichi Manyama, Jul 26 2024

Formula

a(n) = ( 3*A055507(n-1) + 3*A191831(n) + A191829(n) + 2*sigma_0(n) + 3*sigma(n) + sigma_2(n) )/6. - Seiichi Manyama, Jul 26 2024

A059832 A ternary tribonacci triangle: form the triangle as follows: start with 3 single values: 1, 2, 3. Each succeeding row is a concatenation of the previous 3 rows.

Original entry on oeis.org

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

Views

Author

Jason Earls, Feb 25 2001

Keywords

Comments

Alternatively, define a morphism f: 1 -> 2, 2 -> 3, 3 -> 1,2,3; let S(0)=1, S(k) = f(S(k-1)) for k>0; then sequence is the concatenation S(0) S(1) S(2) S(3) ...

Examples

			Rows 0, 1, 2, ..., 8, ... of the triangle are:
0, [1]
1, [2]
2, [3]
3, [1, 2, 3]
4, [2, 3, 1, 2, 3]
5, [3, 1, 2, 3, 2, 3, 1, 2, 3]
6, [1, 2, 3, 2, 3, 1, 2, 3, 3, 1, 2, 3, 2, 3, 1, 2, 3]
7, [2, 3, 1, 2, 3, 3, 1, 2, 3, 2, 3, 1, 2, 3, 1, 2, 3, 2, 3, 1, 2, 3, 3, 1, 2, 3, 2, 3, 1, 2, 3]
8, [3, 1, 2, 3, 2, 3, 1, 2, 3, 1, 2, 3, 2, 3, 1, 2, 3, 3, 1, 2, 3, 2, 3, 1, 2, 3, 2, 3, 1, 2, 3, 3, 1, 2, 3, 2, 3, 1, 2, 3, 1, 2, 3, 2, 3, 1, 2, 3, 3, 1, 2, 3, 2, 3, 1, 2, 3]
...
		

References

  • C. Pickover, Wonders of Numbers, Oxford University Press, NY, 2001, p. 273.

Crossrefs

Cf. A059835. Row sums A001590, row lengths A000213.
Rows 0,3,6,9,12,... converge to A305389, rows 1,4,7,10,... converge to A305390, and rows 2,5,8,11,... converge to A305391.

Programs

  • Maple
    # To get successive rows of A059832
    S:=Array(0..100);
    S[0]:=[1];
    S[1]:=[2];
    S[2]:=[3];
    for n from 3 to 12 do
    S[n]:=[op(S[n-3]),op(S[n-2]), op(S[n-1])];
    lprint(S[n]);
    od: # N. J. A. Sloane, Jul 04 2018

Formula

a(n) = A059825(n) + 1. - Sean A. Irvine, Oct 11 2022

Extensions

More terms from Larry Reeves (larryr(AT)acm.org), Feb 26 2001
Entry revised by N. J. A. Sloane, Jun 21 2018

A059823 Expansion of series related to Liouville's Last Theorem: g.f. sum_{t>0} (-1)^(t+1) *x^(t*(t+1)/2) / ( (1-x^t)^6 *product_{i=1..t} (1-x^i) ).

Original entry on oeis.org

0, 1, 7, 27, 83, 202, 455, 889, 1682, 2892, 4894, 7694, 12090, 17822, 26411, 37206, 52730, 71447, 97984, 128714, 171421, 220064, 285963, 359204, 458506, 565347, 708665, 862163, 1064302, 1276474, 1558090, 1845874, 2226044, 2614188
Offset: 0

Views

Author

N. J. A. Sloane, Feb 24 2001

Keywords

Crossrefs

Cf. A000005 (k=1), A059819 (k=2), A059820 (k=3), ..., A059825 (k=8).

Programs

  • Maple
    Mk := proc(k) -1*add( (-1)^n*q^(n*(n+1)/2)/(1-q^n)^k/mul(1-q^i,i=1..n), n=1..101): end; # with k=6

A059821 Expansion of series related to Liouville's Last Theorem: g.f. sum_{t>0} (-1)^(t+1) *x^(t*(t+1)/2) / ( (1-x^t)^4 *product_{i=1..t} (1-x^i) ).

Original entry on oeis.org

0, 1, 5, 14, 34, 64, 121, 190, 311, 446, 666, 887, 1266, 1599, 2169, 2679, 3504, 4178, 5383, 6253, 7858, 9060, 11114, 12560, 15390, 17076, 20512, 22788, 26993, 29494, 34988, 37750, 44213, 47857, 55281, 59196, 68810, 72754, 83518, 88947
Offset: 0

Views

Author

N. J. A. Sloane, Feb 24 2001

Keywords

Crossrefs

Cf. A000005 (k=1), A059819 (k=2), A059820 (k=3), ..., A059825 (k=8).

Programs

  • Maple
    Mk := proc(k) -1*add( (-1)^n*q^(n*(n+1)/2)/(1-q^n)^k/mul(1-q^i,i=1..n), n=1..101): end; # with k=4

A059822 Expansion of series related to Liouville's Last Theorem: g.f. sum_{t>0} (-1)^(t+1) *x^(t*(t+1)/2) / ( (1-x^t)^5 *product_{i=1..t} (1-x^i) ).

Original entry on oeis.org

0, 1, 6, 20, 55, 119, 246, 435, 766, 1211, 1926, 2807, 4193, 5766, 8161, 10821, 14711, 18820, 24925, 31009, 39984, 48895, 61609, 73844, 91905, 108264, 132400, 154641, 186462, 214772, 257118, 292749, 346430, 392499, 459424, 515579
Offset: 0

Views

Author

N. J. A. Sloane, Feb 24 2001

Keywords

Crossrefs

Cf. A000005 (k=1), A059819 (k=2), A059820 (k=3), ..., A059825 (k=8).

Programs

  • Maple
    Mk := proc(k) -1*add( (-1)^n*q^(n*(n+1)/2)/(1-q^n)^k/mul(1-q^i,i=1..n), n=1..101): end; # with k=5

A059824 Expansion of series related to Liouville's Last Theorem: g.f. Sum_{t>=1} (-1)^(t+1) *x^(t*(t+1)/2) / ( (1-x^t)^7 * Product_{i=1..t} (1-x^i) ).

Original entry on oeis.org

0, 1, 8, 35, 119, 321, 784, 1672, 3389, 6280, 11285, 18971, 31383, 49162, 76322, 113494, 167785, 239086, 340355, 468636, 646058, 865724, 1161936, 1520105, 1997015, 2559758, 3297599, 4157592, 5266644, 6537922, 8168293, 10003615
Offset: 0

Views

Author

N. J. A. Sloane, Feb 24 2001

Keywords

Crossrefs

Cf. A000005 (k=1), A059819 (k=2), A059820 (k=3), ..., A059825 (k=8).

Programs

  • Maple
    Mk := proc(k) -1*add( (-1)^n*q^(n*(n+1)/2)/(1-q^n)^k/mul(1-q^i,i=1..n), n=1..101): end; # with k=7
Showing 1-7 of 7 results.