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 1-5 of 5 results.

A370151 Column 1 of triangle A370040.

Original entry on oeis.org

1, 0, 9, -6, 54, -54, 264, -324, 1127, -1534, 4338, -6274, 15372, -22986, 50846, -77448, 158599, -243696, 470206, -724576, 1333275, -2052498, 3634077, -5575498, 9561408, -14596950, 24368133, -36983308, 60336459, -90983536, 145510968, -217948138, 342546543, -509567136, 788639494
Offset: 2

Views

Author

Paul D. Hanna, Feb 10 2024

Keywords

Comments

The g.f. of triangle A370040, F(x,y), satisfies Sum_{n=-oo..+oo} (-1)^n * (x^n + y*F(x,y))^n = 1 + (y+2)*Sum_{n>=1} (-1)^n * x^(n^2).

Crossrefs

Formula

a(n) = A370040(n,1) for n >= 2.

A370152 Column 2 of triangle A370040.

Original entry on oeis.org

1, 0, 18, -19, 185, -294, 1463, -2715, 9648, -19005, 55413, -111069, 284560, -568913, 1331790, -2630648, 5761619, -11195907, 23296840, -44461191, 88813155, -166422196, 321471340, -591712017, 1111195198, -2010602744, 3685487712, -6561391792, 11775930023, -20647946256, 36371943075
Offset: 3

Views

Author

Paul D. Hanna, Feb 10 2024

Keywords

Comments

The g.f. of triangle A370040, F(x,y), satisfies Sum_{n=-oo..+oo} (-1)^n * (x^n + y*F(x,y))^n = 1 + (y+2)*Sum_{n>=1} (-1)^n * x^(n^2).

Crossrefs

Formula

a(n) = A370040(n,2) for n >= 3.

A370041 Triangle of coefficients T(n,k) in g.f. A(x,y) satisfying Sum_{n=-oo..+oo} (x^n - y*A(x,y))^n = 1 - (y-2)*Sum_{n>=1} x^(n^2), for n >= 1, as read by rows.

Original entry on oeis.org

1, 0, 1, -1, 0, 1, 1, -3, 0, 1, 1, 6, -6, 0, 1, -1, 6, 19, -10, 0, 1, -2, -18, 17, 44, -15, 0, 1, 1, -4, -98, 35, 85, -21, 0, 1, 4, 36, 39, -334, 60, 146, -28, 0, 1, -2, 11, 291, 311, -879, 91, 231, -36, 0, 1, -5, -74, -264, 1310, 1286, -1960, 126, 344, -45, 0, 1, 3, -30, -627, -2547, 4248, 3935, -3892, 162, 489, -55, 0, 1
Offset: 1

Views

Author

Paul D. Hanna, Feb 10 2024

Keywords

Comments

A370031(n) = Sum_{k=0..n-1} T(n,k), for n >= 1.
A355868(n) = Sum_{k=0..n-1} T(n,k) * 2^k, for n >= 1.
A370033(n) = Sum_{k=0..n-1} T(n,k) * 3^k, for n >= 1.
A370034(n) = Sum_{k=0..n-1} T(n,k) * 4^k, for n >= 1.
A370035(n) = Sum_{k=0..n-1} T(n,k) * 5^k, for n >= 1.
A370036(n) = Sum_{k=0..n-1} T(n,k) * 6^k, for n >= 1.
A370037(n) = Sum_{k=0..n-1} T(n,k) * 7^k, for n >= 1.
A370038(n) = Sum_{k=0..n-1} T(n,k) * 8^k, for n >= 1.
A370039(n) = Sum_{k=0..n-1} T(n,k) * 9^k, for n >= 1.
A370043(n) = Sum_{k=0..n-1} T(n,k) * 10^k, for n >= 1.

Examples

			G.f.: A(x,y) = x*(1) + x^2*(0 + y) + x^3*(-1 + y^2) + x^4*(1 - 3*y + y^3) + x^5*(1 + 6*y - 6*y^2 + y^4) + x^6*(-1 + 6*y + 19*y^2 - 10*y^3 + y^5) + x^7*(-2 - 18*y + 17*y^2 + 44*y^3 - 15*y^4 + y^6) + x^8*(1 - 4*y - 98*y^2 + 35*y^3 + 85*y^4 - 21*y^5 + y^7) + x^9*(4 + 36*y + 39*y^2 - 334*y^3 + 60*y^4 + 146*y^5 - 28*y^6 + y^8) + x^10*(-2 + 11*y + 291*y^2 + 311*y^3 - 879*y^4 + 91*y^5 + 231*y^6 - 36*y^7 + y^9) + ...
where
Sum_{n=-oo..+oo} (x^n - y*A(x,y))^n = 1 - (y-2)*Sum_{n>=1} x^(n^2).
TRIANGLE.
This triangle of coefficients T(n,k) of x^n*y^k in g.f. A(x,y) begins
  1;
  0, 1;
  -1, 0, 1;
  1, -3, 0, 1;
  1, 6, -6, 0, 1;
  -1, 6, 19, -10, 0, 1;
  -2, -18, 17, 44, -15, 0, 1;
  1, -4, -98, 35, 85, -21, 0, 1;
  4, 36, 39, -334, 60, 146, -28, 0, 1;
  -2, 11, 291, 311, -879, 91, 231, -36, 0, 1;
  -5, -74, -264, 1310, 1286, -1960, 126, 344, -45, 0, 1;
  3, -30, -627, -2547, 4248, 3935, -3892, 162, 489, -55, 0, 1;
  6, 178, 773, -2626, -12982, 11138, 9989, -7092, 195, 670, -66, 0, 1;
  -4, 40, 1525, 10094, -5842, -48126, 25138, 22258, -12093, 220, 891, -78, 0, 1;
  ...
		

Crossrefs

Cf. A370153 (column 0), A370154 (column 1), A370155 (column 2).
Cf. A370040 (dual triangle).

Programs

  • PARI
    /* Generate A(x, y) by use of definition in name */
    {T(n,k) = my(A=[0,1]); for(i=1,n, A = concat(A,0);
    A[#A] = polcoeff( sum(m=-sqrtint(#A+1),#A, (x^m - y*Ser(A))^m ) - 1 + (y-2)*sum(m=1,sqrtint(#A+1), x^(m^2) ), #A-1)/y ); polcoeff(A[n+1],k,y)}
    for(n=1,15, for(k=0,n-1, print1(T(n,k),", "));print(""))
    
  • PARI
    /* Generate A(x, y) recursively using integration wrt y */
    {T(n, k) = my(A = x +x*O(x^n), M=sqrtint(n+1), Q = sum(m=1, M, x^(m^2)) +x*O(x^n));
    for(i=0, n, A = (1/y) * intformal( Q / sum(m=-M, n, m * (x^m - y*A)^(m-1)), y) +x*O(x^n));
    polcoeff(polcoeff(A, n, x), k, y)}
    for(n=1, 15, for(k=0, n-1, print1(T(n, k), ", ")); print(""))

Formula

G.f. A(x,y) = Sum_{n>=1} T(n,k)*x^n*y^k satisfies the following formulas.
(1) Sum_{n=-oo..+oo} (x^n - y*A(x,y))^n = 1 - (y-2)*Sum_{n>=1} x^(n^2).
(2) Sum_{n=-oo..+oo} x^n * (x^n + y*A(x,y))^(n-1) = 1 - (y-2)*Sum_{n>=1} x^(n^2).
(3) Sum_{n=-oo..+oo} (-1)^n * x^n * (x^n - y*A(x,y))^n = 0.
(4) Sum_{n=-oo..+oo} x^(n^2) / (1 - x^n*y*A(x,y))^n = 1 - (y-2)*Sum_{n>=1} x^(n^2).
(5) Sum_{n=-oo..+oo} x^(n^2) / (1 + x^n*y*A(x,y))^(n+1) = 1 - (y-2)*Sum_{n>=1} x^(n^2).
(6) Sum_{n=-oo..+oo} (-1)^n * x^(n*(n-1)) / (1 - x^n*y*A(x,y))^n = 0.
(7) A(x,y) = (1/y) * Integral Q(x) / Sum_{n=-oo..+oo} n * (x^n - y*A(x,y))^(n-1) dy, where Q(x) = Sum_{n>=1} x^(n^2).
(8) A(x,y=0) = (theta_3(x) - 1)/2 * Product_{n>=1} (1 - x^(4*n-2)) / (1 - x^(4*n)), which is the g.f. of column 0 (A370153) defined at y = 0.

A370020 Table in which the g.f. of row n, R(n,x), satisfies Sum_{k=-oo..+oo} (-1)^k * (x^k + n*R(n,x))^k = 1 + (n+2)*Sum_{k>=1} (-1)^k * x^(k^2), for n >= 1, as read by antidiagonals.

Original entry on oeis.org

1, 1, 1, 1, 2, 4, 1, 3, 7, 9, 1, 4, 12, 25, 22, 1, 5, 19, 53, 85, 63, 1, 6, 28, 99, 234, 301, 155, 1, 7, 39, 169, 529, 1041, 1086, 415, 1, 8, 52, 269, 1054, 2853, 4711, 3927, 1124, 1, 9, 67, 405, 1917, 6667, 15566, 21573, 14328, 2957, 1, 10, 84, 583, 3250, 13893, 42627, 85879, 99484, 52724, 8047, 1, 11, 103, 809, 5209, 26541, 101830, 275211, 477716, 461657, 194915, 21817
Offset: 1

Views

Author

Paul D. Hanna, Feb 09 2024

Keywords

Comments

A related function is theta_4(x) = 1 + 2*Sum_{n>=1} (-1)^n * x^(n^2).

Examples

			This table of coefficients T(n,k) of x^k in R(n,x), n >= 1, k >= 1, begins:
A370021: [1,  1,   4,    9,    22,     63,     155,      415, ...];
A370022: [1,  2,   7,   25,    85,    301,    1086,     3927, ...];
A370023: [1,  3,  12,   53,   234,   1041,    4711,    21573, ...];
A370024: [1,  4,  19,   99,   529,   2853,   15566,    85879, ...];
A370025: [1,  5,  28,  169,  1054,   6667,   42627,   275211, ...];
A370026: [1,  6,  39,  269,  1917,  13893,  101830,   753255, ...];
A370027: [1,  7,  52,  405,  3250,  26541,  219311,  1828657, ...];
A370028: [1,  8,  67,  583,  5209,  47341,  435366,  4039863, ...];
A370029: [1,  9,  84,  809,  7974,  79863,  809131,  8270199, ...];
A370042: [1, 10, 103, 1089, 11749, 128637, 1423982, 15898231, ...];
...
where the n-th row function R(n,x) satisfies
Sum_{k=-oo..+oo} (-1)^k * (x^k + n*R(n,x))^k = 1 + (n+2)*Sum_{k>=1} (-1)^k * x^(k^2).
		

Crossrefs

Programs

  • PARI
    {T(n,k) = my(A=[0,1]); for(i=0,k, A = concat(A,0);
    A[#A] = polcoeff( sum(m=-#A,#A, (-1)^m * (x^m + n*Ser(A))^m ) - 1 - (n+2)*sum(m=1,#A, (-1)^m * x^(m^2) ), #A-1)/n ); A[k+1]}
    for(n=1,12, for(k=1,10, print1(T(n,k),", "));print(""))

Formula

The n-th row g.f. R(n,x) = Sum_{k>=1} T(n,k)*x^k satisfies the following formulas.
(1) Sum_{k=-oo..+oo} (-1)^k * (x^k + n*R(n,x))^k = 1 + (n+2)*Sum_{k>=1} (-1)^k * x^(k^2).
(2) Sum_{k=-oo..+oo} (-1)^k * x^k * (x^k + n*R(n,x))^(k-1) = 1 + (n+2)*Sum_{k>=1} (-1)^k * x^(k^2).
(3) Sum_{k=-oo..+oo} (-1)^k * x^k * (x^k + n*R(n,x))^k = 0.
(4) Sum_{k=-oo..+oo} (-1)^k * x^(k^2) / (1 + n*R(n,x)*x^k)^k = 1 + (n+2)*Sum_{k>=1} (-1)^k * x^(k^2).
(5) Sum_{k=-oo..+oo} (-1)^k * x^(k^2) / (1 + n*R(n,x)*x^k)^(k+1) = 1 + (n+2)*Sum_{k>=1} (-1)^k * x^(k^2).
(6) Sum_{k=-oo..+oo} (-1)^k * x^(k*(k+1)) / (1 + n*R(n,x)*x^k)^(k+1) = 0.

A370150 Expansion of g.f. (1 - theta_4(x))/2 / Product_{n>=1} (1 - x^(2*n))^3.

Original entry on oeis.org

1, 0, 3, -1, 9, -3, 22, -9, 52, -22, 111, -51, 230, -108, 451, -222, 861, -432, 1587, -819, 2861, -1501, 5028, -2691, 8679, -4707, 14691, -8089, 24492, -13638, 40202, -22653, 65141, -37060, 104199, -59863, 164833, -95484, 257920, -150646, 399681, -235141, 613557, -363543, 933869
Offset: 1

Views

Author

Paul D. Hanna, Feb 10 2024

Keywords

Comments

Column 0 of triangle A370040. The g.f. of triangle A370040, F(x,y), satisfies Sum_{n=-oo..+oo} (-1)^n * (x^n + y*F(x,y))^n = 1 + (y+2)*Sum_{n>=1} (-1)^n * x^(n^2). The g.f. of this sequence is F(x,y) at y = 0.

Examples

			G.f.: A(x) = x + 3*x^3 - x^4 + 9*x^5 - 3*x^6 + 22*x^7 - 9*x^8 + 52*x^9 - 22*x^10 + 111*x^11 - 51*x^12 + 230*x^13 - 108*x^14 + 451*x^15 - 222*x^16 + ...
which equals A(x) = P(x) / Q(x)
where
P(x) = x - x^4 + x^9 - x^16 + x^25 - x^36 + x^49 + ...
Q(x) = 1 - 3*x^2 + 5*x^6 - 7*x^12 + 9*x^20 - 11*x^30 + 13*x^42 + ...
		

Crossrefs

Cf. A370153 (dual).

Programs

  • PARI
    {a(n) = my(P = sum(m=1,sqrtint(n+1), (-1)^(m-1) * x^(m^2) +x*O(x^n)),
    Q = sum(m=0,sqrtint(n+1), (-1)^m * (2*m+1) * x^(m*(m+1)) +x*O(x^n)));
    polcoeff(P/Q,n)}
    for(n=1,50,print1(a(n),", "))

Formula

a(n) = A370040(n,0) for n >= 1.
G.f. A(x) = Sum_{n>=1} a(n)*x^n satisfies the following formulas.
(1) A(x) = (1 - theta_4(x))/2 / Product_{n>=1} (1 - x^(2*n))^3.
(2) A(x) = P(x)/Q(x) where P(x) = Sum_{n>=1} (-1)^(n-1) * x^(n^2) and Q(x) = Sum_{n>=0} (-1)^n * (2*n+1) * x^(n*(n+1)).
(3) A(x) = F(x,0) where F(x,y) is the g.f. of triangle A370040 (see comment).
Showing 1-5 of 5 results.