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 1-3 of 3 results.

A353997 Partial sums of A078473.

Original entry on oeis.org

1, 1, 1, 6, 12, 12, 12, 12, 22, 22, 46, 46, 46, 46, 46, 67, 67, 67, 107, 137, 137, 137, 137, 137, 168, 168, 168, 168, 228, 228, 292, 292, 292, 292, 292, 342, 342, 342, 342, 342, 426, 426, 426, 546, 606, 606, 606, 606, 656, 656, 656, 656, 656, 656, 800, 800, 800
Offset: 1

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Author

Amiram Eldar, May 13 2022

Keywords

Crossrefs

Programs

  • Mathematica
    f[p_, e_] := Which[p == 5, (5^(e + 1) - 1)/4, (m = Mod[p, 5]) == 2 || m == 3, If[EvenQ[e], (p^(e + 2) - 1)/(p^2 - 1), 0], m == 1 || m == 4, Sum[(k + 1)*(e - k + 1)*p^k, {k, 0, e}]]; s[1] = 1; s[n_] := Times @@ f @@@ FactorInteger[n]; Accumulate[Array[s, 100]]

Formula

a(n) = Sum_{k=1..n} A078473(k).
a(n) ~ c*n^2 where c = 2*Pi^4*log(phi)/375 = 0.2499968345... and phi is the golden ratio (1+sqrt(5))/2 (A001622) (Baake and Moody, 1999).

A035282 Expansion of zeta function of icosian ring (nonzero terms).

Original entry on oeis.org

1, 5, 6, 10, 24, 21, 40, 30, 31, 60, 64, 50, 84, 120, 60, 50, 144, 120, 124, 85, 144, 200, 160, 126, 91, 180, 240, 240, 155, 204, 220, 300, 410, 320, 156, 264, 280, 210, 360, 300, 304, 384, 420, 170, 400, 504, 360, 300, 364, 384, 250, 400, 504, 960, 424, 720, 310
Offset: 1

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Author

Keywords

Comments

Let zetaI(s) be the zeta function of icosian ring: zetaI(s) = zetaQ(tau)(2s)*zetaQ(tau)(2s-1) where zetaQ(tau)(s) is defined in A035187; then zetaI(s) = Sum_{n>=1} a(n)/n^(2s).
Nonzero terms of A078473. - Michel Marcus, Mar 03 2014

Crossrefs

Programs

  • Mathematica
    f[p_, e_] := Which[p == 5, (5^(e + 1) - 1)/4, (m = Mod[p, 5]) == 2 || m == 3, If[EvenQ[e], (p^(e + 2) - 1)/(p^2 - 1), 0], m == 1 || m == 4, Sum[(k + 1)*(e - k + 1)*p^k, {k, 0, e}]]; s[1] = 1; s[n_] := Times @@ f @@@ FactorInteger[n]; Select[Array[s, 200], # > 0 &] (* Amiram Eldar, May 13 2022 *)

A035111 Numerators in expansion of a certain Dirichlet series.

Original entry on oeis.org

1, 5, 6, 10, 24, 20, 40, 30, 30, 60, 64, 50, 84, 120, 60, 50, 144, 120, 124, 80, 144, 200, 160, 120, 90, 180, 240, 240, 150, 204, 220, 300, 408, 320, 150, 264, 280, 200, 360, 300, 304, 384, 420, 170, 400, 480, 360, 300, 364, 384, 250, 400, 504, 960, 424, 720, 300
Offset: 0

Views

Author

Keywords

Comments

This is the SO(3) case, whereas the SO(4) case is reported in A078473 and A035282. [From R. J. Mathar, Jul 16 2010]

Extensions

More terms from R. J. Mathar, Jul 16 2010
Showing 1-3 of 3 results.