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.

A048386 Numbers n such that replacing digits d in decimal expansion of n with d^2 yields a square.

Original entry on oeis.org

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 23, 43, 49, 61, 100, 122, 136, 148, 163, 200, 221, 244, 269, 300, 305, 366, 400, 481, 488, 500, 600, 629, 700, 800, 884, 900, 1105, 1127, 1222, 1241, 1281, 1438, 1522, 1641, 1805, 2300, 2405, 2722, 2966, 3203, 4205, 4300, 4402
Offset: 1

Views

Author

Patrick De Geest, Mar 15 1999

Keywords

Examples

			2722 = (2)(7)(2)(2) -> (4)(49)(4)(4) = 44944 = 212^2 and square.
		

Crossrefs

Programs

  • Magma
    f:=func; [0] cat [k:k in [1..4500]|IsSquare(f(k))]; // Marius A. Burtea, Feb 13 2020