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.

A037428 Positive numbers having the same set of digits in base 4 and base 10.

Original entry on oeis.org

1, 2, 3, 13, 31, 123, 203, 231, 1031, 1103, 1120, 1203, 1230, 1303, 2103, 2120, 2201, 2300, 2301, 2302, 2303, 3012, 3020, 3021, 3022, 3023, 3100, 3101, 3102, 3103, 3200, 3201, 3202, 3203, 3320, 10023, 10032, 10123, 10132, 10232, 10323, 10332
Offset: 1

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Keywords

Examples

			1103 is in the sequence because 1103 in base 4 is 101033.
		

Crossrefs

Subsequence of A007090 and A037392.

Programs

  • Mathematica
    Select[Range[33333],Union[IntegerDigits[#]]==Union[IntegerDigits[#,4]]&] (* Harvey P. Dale, Jan 01 2023 *)
  • PARI
    is(n)=Set(digits(n, 4))==Set(digits(n)) \\ Charles R Greathouse IV, Feb 11 2017

Extensions

Corrected by Don Reble, Apr 28 2006
Edited by John Cerkan, Feb 09 2017