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.

A321567 Expansion of Product_{1 <= i_1 <= i_2 <= i_3 <= i_4} (1 + x^(i_1*i_2*i_3*i_4)).

Original entry on oeis.org

1, 1, 1, 2, 3, 4, 6, 8, 11, 16, 21, 27, 38, 49, 63, 84, 109, 138, 180, 228, 289, 369, 463, 578, 732, 911, 1128, 1407, 1741, 2140, 2646, 3243, 3967, 4861, 5924, 7196, 8767, 10616, 12827, 15516, 18707, 22486, 27054, 32440, 38835, 46488, 55502, 66136, 78836, 93727, 111265
Offset: 0

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Author

Seiichi Manyama, Nov 13 2018

Keywords

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Crossrefs

Product_{1 <= i_1 <= i_2 <= ... <= i_b} (1 + x^(i_1 * i_2 * ... * i_b)): A000009 (b=1), A211856 (b=2), A321359 (b=3), this sequence (b=4).
Cf. A066806, A218320, A321566.

Formula

G.f.: Product_{k>0} (1 + x^k)^A218320(k).

A319517 Expansion of Product_{1 <= i_1 <= i_2 <= i_3 <= i_4} (1 - x^(i_1*i_2*i_3*i_4)).

Original entry on oeis.org

1, -1, -1, 0, -1, 2, 0, 2, -1, 0, 3, -1, -2, -1, 1, -6, -1, 0, 0, 0, 7, -1, 1, -2, 4, 1, -2, 11, 1, -2, -10, 11, -11, 15, -16, -6, -7, -10, -1, 10, -5, -10, 12, -20, 19, -16, 24, -2, 28, -9, 41, -6, 15, 20, 4, -21, -15, -13, -14, 13, -73, 67, -30, -44, -19, 31, -30
Offset: 0

Views

Author

Seiichi Manyama, Nov 14 2018

Keywords

Links

Crossrefs

Convolution inverse of A321566.
Product_{1 <= i_1 <= i_2 <= ... <= i_b} (1 - x^(i_1 * i_2 * ... * i_b)): A010815 (b=1), A321299 (b=2), A321361 (b=3), this sequence (b=4).
Cf. A218320, A321460, A321567.

Formula

G.f.: Product_{k>0} (1 - x^k)^A218320(k).
Showing 1-2 of 2 results.

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