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.

A138174 a(n) is the smallest cube that begins with n^2.

Original entry on oeis.org

1, 4096, 9261, 166375, 250047, 3652264, 4913, 64, 8120601, 1000, 12167, 1442897, 16974593, 19683, 225866529, 25672375, 28934443, 3241792, 3616805375, 40001688, 4410944, 4843965888, 529475129, 5764224257, 62570773, 676836152
Offset: 1

Views

Author

Zak Seidov, Mar 05 2008

Keywords

Comments

Differs from A030690.

Crossrefs

Cf. A030690, A030691, A018852, A018797, A077729, A077730, A138173.

Formula

a(n) = (A138173(n))^3.

Extensions

Corrected by D. S. McNeil, Dec 12 2010

A197722 Smallest number k such that k^2 begins with n^3.

Original entry on oeis.org

1, 9, 52, 8, 112, 147, 586, 716, 27, 100, 1154, 4157, 4688, 5239, 581, 64, 22166, 2415, 2619, 28285, 30432, 10319, 34882, 37181, 125, 41924, 44366, 46853, 15617, 51962, 54582, 18102, 59948, 62693, 207063, 216, 71171, 74076, 77019, 800, 83019, 272192, 28197
Offset: 1

Views

Author

Michel Lagneau, Oct 17 2011

Keywords

Examples

			a(6) = 147 because 147^2 = 21609 starts with 216 = 6^3.

Crossrefs

See A138173 (smallest m such that m^3 begins with n^2).

Programs

  • Mathematica
    f[n_]:=Block[{k = 0, m}, While[m = Max[0, Floor@Log[10, k^2]-Floor@Log[10, n^3]]; (k^2-Mod[k^2, 10^m])/10^m != n^3, k++]; k]; Array[f, 43]
Showing 1-2 of 2 results.

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

Content is available under The OEIS End-User License Agreement.