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.

A005886 Theta series of f.c.c. lattice with respect to tetrahedral hole.

Original entry on oeis.org

4, 12, 12, 16, 24, 12, 24, 36, 12, 28, 36, 24, 36, 36, 24, 24, 60, 36, 28, 48, 12, 60, 60, 24, 48, 48, 36, 48, 60, 24, 52, 84, 48, 24, 60, 36, 48, 96, 36, 72, 48, 36, 72, 60, 48, 52, 96, 36, 60, 96, 24, 72, 108, 24, 48, 60, 72, 96, 84, 60, 48, 108, 36, 52, 72, 60, 108, 108, 36, 48, 108
Offset: 0

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Author

N. J. A. Sloane

Keywords

Comments

Empirically, the number of integral quadruples with sum = 1, sum-of-squares = 2n-1. - Colin Mallows, Dec 31 2016

Examples

			4 + 12*x + 12*x^2 + 16*x^3 + 24*x^4 + 12*x^5 + 24*x^6 + 36*x^7 + 12*x^8 + ...

References

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

Links

Crossrefs

Cf. A005869, A005878, A008443. Partial sums is A121054. Cf also A278081-A278086.

Programs

Formula

a(n) = 1/2 * A005878(n) = 2 * A005869(n) = 4 * A008443(n). - Michael Somos, May 31 2012

Extensions

Terms a(50) onward added by G. C. Greubel, Feb 20 2018

A121055 Sizes of successive clusters in b.c.c. lattice centered at midpoint of a short edge.

Original entry on oeis.org

2, 8, 14, 22, 34, 40, 52, 70, 76, 90, 108, 120, 138, 156, 168, 180, 210, 228, 242, 266, 272, 302, 332, 344, 368, 392, 410, 434, 464, 476, 502, 544, 568, 580, 610, 628, 652, 700, 718, 754, 778, 796, 832, 862, 886, 912, 960, 978, 1008, 1056
Offset: 0

Views

Author

N. J. A. Sloane, Aug 09 2006

Keywords

References

  • N. J. A. Sloane and B. K. Teo, Theta series and magic numbers for close-packed spherical clusters, J. Chem. Phys. 83 (1985) 6520-6534.

Crossrefs

Partial sums of A005869. Equals 2*A038835 and also A121054/2. Cf. A008443.
Showing 1-2 of 2 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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