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

Author

Antti Karttunen, Aug 17 2013

Keywords

• nonn

Comments

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

Examples

			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.
		

Links

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

Crossrefs

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