A045109 Numbers whose base-4 representation contains exactly four 1's and four 2's.

21930, 22122, 22170, 22182, 22185, 22890, 22938, 22950, 22953, 23130, 23142, 23145, 23190, 23193, 23205, 25962, 26010, 26022, 26025, 26202, 26214, 26217, 26262, 26265, 26277, 26970, 26982, 26985, 27030, 27033

Offset

1,1

Links

Table of n, a(n) for n=1..30.

Mathematica

Select[Range[27200], DigitCount[#, 4, 1]==DigitCount[#, 4, 2]==4&] (* Harvey P. Dale, Jul 19 2019 *)

Crossrefs

Cf. A007090.

Sequence in context: A345155 A345156 A031647 * A206126 A077751 A066693

Adjacent sequences: A045106 A045107 A045108 * A045110 A045111 A045112

Keyword

nonn,base

Author

Clark Kimberling

Status

approved