A228236 Numbers k for which a sum k+bitcount(k) can be also obtained as a sum k2 +bitcount(k2) for some other k2<>k . Here bitcount(k) (A000120) gives the number of 1's in binary representation of nonnegative integer k.

3, 4, 11, 12, 14, 15, 16, 17, 19, 20, 27, 28, 29, 31, 32, 34, 35, 36, 43, 44, 46, 47, 48, 49, 51, 52, 59, 60, 62, 65, 67, 68, 75, 76, 78, 79, 80, 81, 83, 84, 91, 92, 93, 95, 96, 98, 99, 100, 107, 108, 110, 111, 112, 113, 115, 116, 123, 124, 125, 126, 127, 128

Offset

1,1

Comments

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

Links

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

Example

0 is not in this sequence because the sum 0+A000120(0)=0 cannot be obtained with any other value of k than k=0.
1 is not in this sequence because the sum 1+A000120(1)=2 cannot be obtained with any other value of k than k=1.
2 is not in this sequence because the sum 2+A000120(2)=3 cannot be obtained with any other value of k than k=2.
3 IS in this sequence because the sum 3+A000120(3)=5 can also be obtained with value k=4, as also 4+A000120(4)=5, and thus also 4 is in this sequence.

Prog

(Scheme) ;; With Antti Karttunen's IntSeq-library
(define A228236 (MATCHING-POS 1 0 (lambda (k) (> (A228085 (A092391 k)) 1))))

Crossrefs

Complement: A228090. Subsets: A228091, A228237. Cf. also A092391, A228085.

Sequence in context: A195589 A339578 A244005 * A344346 A047457 A226632

Adjacent sequences: A228233 A228234 A228235 * A228237 A228238 A228239

Keyword

nonn

Author

Antti Karttunen, Aug 17 2013

Status

approved