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.

A063243 Duplicate of A063232.

Original entry on oeis.org

5, 16, 24, 36, 44, 56, 64, 76, 84, 96, 104, 116, 124, 136, 144, 156, 164, 176, 184, 196, 204, 216, 224, 236, 244, 256, 264, 276, 284, 296, 304, 316, 324, 336, 344, 356, 364, 376, 384, 396, 404, 416, 424, 436, 444, 456, 464, 476, 484, 496
Offset: 1

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Author

Keywords

A063289 Dimension of the space of weight n cuspidal newforms for Gamma_1( 16 ).

Original entry on oeis.org

-1, 2, 7, 11, 16, 20, 25, 29, 34, 38, 43, 47, 52, 56, 61, 65, 70, 74, 79, 83, 88, 92, 97, 101, 106, 110, 115, 119, 124, 128, 133, 137, 142, 146, 151, 155, 160, 164, 169, 173, 178, 182, 187, 191, 196, 200, 205, 209, 214, 218, 223, 227, 232, 236
Offset: 2

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Author

N. J. A. Sloane, Jul 14 2001

Keywords

Comments

It appears that for n > 2 a(n) = floor((9n-22)/2). - Gary Detlefs, Mar 02 2010

Crossrefs

Cf. A063232, A063233, A017185 (bisection), A130880, A332438.

Programs

  • Mathematica
    Join[{-1}, Table[9*n/2 + (-1)^n/4 - 45/4, {n, 3, 60}]] (* Amiram Eldar, Jan 12 2024 *)

Formula

a(n) = 9*n/2 + (-1)^n/4 - 45/4 for n >= 3, with first differences in A010710. - R. J. Mathar, Dec 06 2010
From M. F. Hasler, Mar 05 2012: (Start)
G.f.: x^2*(-1 + 3*x + 6*x^2 + x^3)/(1 - x - x^2 + x^3).
a(n+2) = a(n)+9 (n>2), a(2n+1) = a(2n)+4 (n>1), a(2n) = a(2n-1)+5 (n>1). (End)
Sum_{n>=3} (-1)^(n+1)/a(n) = cot(2*Pi/9)*Pi/9. - Amiram Eldar, Jan 12 2024
From Amiram Eldar, Nov 22 2024: (Start)
Product_{n>=3} (1 - (-1)^n/a(n)) = 2*sin(Pi/18) + 1 (= A130880 + 1).
Product_{n>=3} (1 + (-1)^n/a(n)) = (1/2) * sec(Pi/9) (= A332438 - 3). (End)
Showing 1-2 of 2 results.