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.

A226969 Numbers whose base-4 sum of digits is 4.

Original entry on oeis.org

7, 10, 13, 19, 22, 25, 28, 34, 37, 40, 49, 52, 67, 70, 73, 76, 82, 85, 88, 97, 100, 112, 130, 133, 136, 145, 148, 160, 193, 196, 208, 259, 262, 265, 268, 274, 277, 280, 289, 292, 304, 322, 325, 328, 337, 340, 352, 385, 388, 400, 448, 514, 517, 520, 529, 532
Offset: 1

Views

Author

Tom Edgar, Sep 01 2013

Keywords

Comments

Subsequence of A016777. - Michel Marcus, Sep 03 2013
In general, the set of numbers with sum of base-b digits equal to b is a subset of { (b-1)*k + 1; k = 2, 3, 4, ... }. - M. F. Hasler, Dec 23 2016

Examples

			The quaternary expansion of 13 is (3,1), which has sum of digits 4.
The quaternary expansion of 40 is (2,2,0), which has sum of digits 4.
17 is not on the list since the quaternary expansion of 17 is (1,0,1), which has sum of digits 2 not 4.
		

Crossrefs

Cf. A226636 (b = 3), A227062 (b = 5), A227080 (b = 6), A227092 (b = 7), A227095 (b = 8), A227238 (b = 9), A052224 (b = 10).

Programs

  • Mathematica
    Select[Range@ 540, Total@ IntegerDigits[#, 4] == 4 &] (* Michael De Vlieger, Dec 23 2016 *)
  • PARI
    select( is(n)=sumdigits(n,4)==4, [1..999]) \\ M. F. Hasler, Dec 23 2016
    
  • Python
    agen = A226636gen(sod=4, base=4) # generator of terms using code in A226636
    print([next(agen) for n in range(1, 57)]) # Michael S. Branicky, Jul 10 2022
  • Sage
    [i for i in [0..1000] if sum(Integer(i).digits(base=4))==4]