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A230092 Numbers of the form k + wt(k) for exactly three distinct k, where wt(k) = A000120(k) is the binary weight of k. 12

%I

%S 129,134,386,391,515,518,642,647,899,904,1028,1030,1154,1159,1411,

%T 1416,1540,1543,1667,1672,1924,1929,2178,2183,2435,2440,2564,2567,

%U 2691,2696,2948,2953,3077,3079,3203,3208,3460,3465,3589,3592,3716,3721,3973,3978,4226

%N Numbers of the form k + wt(k) for exactly three distinct k, where wt(k) = A000120(k) is the binary weight of k.

%C The positions of entries equal to 3 in A228085, or numbers that appear exactly thrice in A092391.

%C Numbers that can be expressed as the sum of distinct terms of the form 2^n+1, n=0,1,... in exactly three ways.

%H Reinhard Zumkeller and Donovan Johnson, <a href="/A230092/b230092.txt">Table of n, a(n) for n = 1..10000</a> (first 1000 terms from Reinhard Zumkeller)

%H <a href="/index/Coi#Colombian">Index entries for Colombian or self numbers and related sequences</a>

%p For Maple code see A230091.

%o (Haskell)

%o a230092 n = a230092_list !! (n-1)

%o a230092_list = filter ((== 3) . a228085) [1..]

%o -- _Reinhard Zumkeller_, Oct 13 2013

%Y Cf. A000120, A010061, A228088, A230058, A230091.

%Y Cf. A227915.

%K nonn,base

%O 1,1

%A _N. J. A. Sloane_, Oct 10 2013

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Last modified October 14 05:08 EDT 2019. Contains 327995 sequences. (Running on oeis4.)