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.

A217513 Partial sums of nonzero terms in A005926.

Original entry on oeis.org

2, 8, 20, 32, 38, 56, 74, 86, 116, 130, 136, 166, 190, 208, 238, 264, 288, 318, 342, 360, 384, 420, 444, 492, 522, 534, 588, 612, 648, 690, 714, 732, 768, 822, 840, 894, 942, 966, 1026, 1050, 1068, 1134, 1190, 1220, 1256, 1280, 1310, 1382, 1418, 1448, 1508
Offset: 0

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Author

N. J. A. Sloane, Oct 05 2012

Keywords

Comments

Sizes of clusters of atoms in diamond structure.

Crossrefs

Extensions

More terms from Andy Huchala, May 17 2023

A045840 a(n) = A005926(n)/2.

Original entry on oeis.org

0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 6, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 6, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 9, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 9, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 6
Offset: 0

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Author

Keywords

Crossrefs

Cf. A005926.

Extensions

More terms (computed from those of A005926) by Antti Karttunen, Jul 24 2017

A005925 Theta series of diamond.

Original entry on oeis.org

1, 0, 0, 4, 0, 0, 0, 0, 12, 0, 0, 12, 0, 0, 0, 0, 6, 0, 0, 12, 0, 0, 0, 0, 24, 0, 0, 16, 0, 0, 0, 0, 12, 0, 0, 24, 0, 0, 0, 0, 24, 0, 0, 12, 0, 0, 0, 0, 8, 0, 0, 24, 0, 0, 0, 0, 48, 0, 0, 36, 0, 0, 0, 0, 6, 0, 0, 12
Offset: 0

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Author

Keywords

Comments

a(n) > 0 iff n is in A047470. - Robert Israel, Jul 06 2016

References

  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Programs

  • Maple
    S:= series((JacobiTheta2(0,z^4)^3 + JacobiTheta3(0,z^4)^3 + JacobiTheta4(0,z^4)^3)/2, z, 101):
    seq(coeff(S,z,j),j=0..100); # Robert Israel, Jul 06 2016
  • Mathematica
    terms = 68; s = Simplify[Normal[(EllipticTheta[2, 0, z^4]^3 + EllipticTheta[3, 0, z^4]^3 + EllipticTheta[4, 0, z^4]^3)/2 + O[z]^terms], z > 0]; CoefficientList[s, z] (* Jean-François Alcover, Jul 07 2017 *)

Formula

(theta_2^3 + theta_3^3 + theta_4^3) / 2.
Showing 1-3 of 3 results.