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 1-2 of 2 results.

A320251 Square array A(n,k), n>=0, k>=0, read by antidiagonals, where column k is the expansion of 1/(1 - Sum_{j>=1} j^k*x^j).

Original entry on oeis.org

1, 1, 1, 1, 1, 2, 1, 1, 3, 4, 1, 1, 5, 8, 8, 1, 1, 9, 18, 21, 16, 1, 1, 17, 44, 63, 55, 32, 1, 1, 33, 114, 207, 221, 144, 64, 1, 1, 65, 308, 723, 991, 776, 377, 128, 1, 1, 129, 858, 2631, 4805, 4752, 2725, 987, 256, 1, 1, 257, 2444, 9843, 24655, 31880, 22769, 9569, 2584, 512
Offset: 0

Views

Author

Ilya Gutkovskiy, Oct 08 2018

Keywords

Comments

A(n,k) is the invert transform of k-th powers evaluated at n.

Examples

			G.f. of column k: A_k(x) = 1 + x + (2^k + 1)*x^2 + (2^(k + 1) + 3^k + 1)*x^3 + (3*2^k + 2^(2*k + 1) + 2*3^k + 1)*x^4 + ...
Square array begins:
   1,   1,    1,    1,     1,      1,  ...
   1,   1,    1,    1,     1,      1,  ...
   2,   3,    5,    9,    17,     33,  ...
   4,   8,   18,   44,   114,    308,  ...
   8,  21,   63,  207,   723,   2631,  ...
  16,  55,  221,  991,  4805,  24655,  ...
		

Crossrefs

Columns k=0..3 give A011782, A088305, A033453, A144109.
Main diagonal gives A301655.
Cf. A144048.

Programs

  • Mathematica
    Table[Function[k, SeriesCoefficient[1/(1 - Sum[i^k x^i, {i, 1, n}]), {x, 0, n}]][j - n], {j, 0, 10}, {n, 0, j}] // Flatten
    Table[Function[k, SeriesCoefficient[1/(1 - PolyLog[-k, x]), {x, 0, n}]][j - n], {j, 0, 10}, {n, 0, j}] // Flatten

Formula

G.f. of column k: 1/(1 - PolyLog(-k,x)), where PolyLog() is the polylogarithm function.

A320257 a(n) = [x^n] 1/(1 + Sum_{k>=1} k^n*x^k).

Original entry on oeis.org

1, -1, -3, -12, 115, 10801, 513128, -31622305, -29139002795, -10674262825020, 8501486817673047, 49739414341982655313, 119603027548636893292304, -1457935338988787721752835601, -53309412371631686621966575526695, -722987647385617983636099803915844108
Offset: 0

Views

Author

Ilya Gutkovskiy, Oct 08 2018

Keywords

Crossrefs

Programs

  • Mathematica
    Table[SeriesCoefficient[1/(1 + Sum[k^n x^k, {k, 1, n}]), {x, 0, n}], {n, 0, 15}]
    Table[SeriesCoefficient[1/(1 + PolyLog[-n, x]), {x, 0, n}], {n, 0, 15}]

Formula

a(n) = [x^n] 1/(1 + PolyLog(-n,x)), where PolyLog() is the polylogarithm function.
Showing 1-2 of 2 results.