login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A228090 Numbers k for which a sum k + bitcount(k) cannot be obtained as a sum k2 + bitcount(k2) for any other k2<>k . Here bitcount(k) (A000120) gives the number of 1's in binary representation of nonnegative integer k. 4
0, 1, 2, 5, 6, 7, 8, 9, 10, 13, 18, 21, 22, 23, 24, 25, 26, 30, 33, 37, 38, 39, 40, 41, 42, 45, 50, 53, 54, 55, 56, 57, 58, 61, 63, 64, 66, 69, 70, 71, 72, 73, 74, 77, 82, 85, 86, 87, 88, 89, 90, 94, 97, 101, 102, 103, 104, 105, 106, 109, 114, 117, 118, 119, 120 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

In other words, numbers k such that A228085(A092391(k)) = 1.

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..10000

Index entries for Colombian or self numbers and related sequences

EXAMPLE

0 is in this sequence because the sum 0+A000120(0)=0 cannot be obtained with any other value of k than k=0.

1 is in this sequence because the sum 1+A000120(1)=2 cannot be obtained with any other value of k than k=1.

2 is in this sequence because the sum 2+A000120(2)=3 cannot be obtained with any other value of k than k=2.

3 is not in this sequence because the sum 3+A000120(3)=5 can also be obtained with value k=4, as also 4+A000120(4)=5.

PROG

(Scheme, with Antti Karttunen's IntSeq-library) (define A228090 (MATCHING-POS 1 0 (lambda (k) (= 1 (A228085 (A092391 k))))))

CROSSREFS

Sequence A228089 sorted into ascending order. Complement: A228236.

Cf. also A092391, A228085, A228088.

Sequence in context: A047581 A039067 A202114 * A287440 A111175 A047326

Adjacent sequences:  A228087 A228088 A228089 * A228091 A228092 A228093

KEYWORD

nonn,base

AUTHOR

Antti Karttunen, Aug 17 2013

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 17 04:03 EDT 2019. Contains 327119 sequences. (Running on oeis4.)