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.

Previous Showing 11-12 of 12 results.

A036095 Centered cube numbers: a(n) = (n+1)^17 + n^17.

Original entry on oeis.org

1, 131073, 129271235, 17309009347, 780119322309, 17689598897861, 249557173431943, 2484430327672455, 18928981513351817, 116677181699666569, 605447028499293771, 2724058135239730763, 10869027026121774925
Offset: 0

Views

Author

Keywords

Comments

Never prime, as a(n) = (2n + 1) * (n^16 + 8n^15 + 64n^14 + 308n^13 + 1036n^12 + 2576n^11 + 4900n^10 + 7274n^9 + 8518n^8 + 7896n^7 + 5776n^6 + 3300n^5 + 1444n^4 + 468n^3 + 106n^2 + 15n + 1). Semiprime for n in {1, 5, 21, 29, 33, ...}. - Jonathan Vos Post, Aug 27 2011

References

  • B. K. Teo and N. J. A. Sloane, Magic numbers in polygonal and polyhedral clusters, Inorgan. Chem. 24 (1985), 4545-4558.

Crossrefs

Programs

A194566 Centered cube numbers: (n+1)^100+n^100.

Original entry on oeis.org

1, 1267650600228229401496703205377, 515377520732011332304111729993850674198810727377, 1606938044259505653062694103672199063651968615055494942823377
Offset: 0

Views

Author

Jonathan Vos Post, Aug 29 2011

Keywords

Comments

Can never be prime, and after a(0) must have at least 3 prime factors, as a(n) = (2*n^4 + 4*n^3 + 6*n^2 + 4*n + 1) * p_16(n) * p_80(n).

Crossrefs

Programs

  • Maple
    a:= n-> (n+1)^100 +n^100: seq (a(n), n=0..20);
  • Mathematica
    Total/@Partition[Range[0,5]^100,2,1] (* Harvey P. Dale, Aug 10 2013 *)

Formula

a(n) = (n+1)^100 + n^100.
Previous Showing 11-12 of 12 results.