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.

A115689 Powerful(1) numbers (A001694) whose digit reversal is a square.

Original entry on oeis.org

1, 4, 9, 100, 121, 144, 169, 400, 441, 484, 675, 676, 900, 961, 1000, 1089, 1800, 4000, 9000, 9801, 10000, 10201, 10404, 10609, 12100, 12321, 12544, 12769, 14400, 14641, 14884, 16900, 18000, 18252, 40000, 40401, 40804, 44100, 44521, 44944
Offset: 1

Views

Author

Giovanni Resta, Jan 31 2006

Keywords

Examples

			18252=2^2*3^3*13^2 is powerful and 25281=159^2.
		

Crossrefs

Programs

  • Mathematica
    Join[{1},Select[Range[50000],Min[FactorInteger[#][[All,2]]]>1&& IntegerQ[ Sqrt[ IntegerReverse[#]]]&]] (* Harvey P. Dale, Aug 08 2020 *)