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.

A063145 Composite numbers not divisible by 2 which in base 4 contain their largest proper factor as a substring.

Original entry on oeis.org

407, 1189, 1343, 1681, 7597, 8791, 10579, 16147, 23479, 24341, 25751, 26101, 28757, 34093, 36349, 39961, 47053, 47669, 52891, 58879, 62263, 64277, 79223, 88183, 93829, 96029, 98261
Offset: 1

Views

Author

Robert G. Wilson v, Aug 08 2001

Keywords

Crossrefs

Cf. A062238.

Programs

  • Mathematica
    Do[ If[ !PrimeQ[ n ] && StringPosition[ ToString[ FromDigits[ IntegerDigits[ n, 4 ] ] ], ToString[ FromDigits[ IntegerDigits[ Divisors[ n ][ [ -2 ] ], 4 ] ] ] ] != {}, Print[ n ] ], {n, 3, 10^5, 2} ]