A118179 Numbers which occur only once in A005229.

2, 4, 5, 8, 9, 11, 13, 14, 15, 18, 21, 22, 23, 25, 27, 28, 31, 32, 33, 34, 35, 38, 40, 41, 42, 44, 47, 48, 49, 50, 51, 52, 55, 56, 57, 60, 61, 62, 65, 67, 68, 70, 71, 72, 73, 74, 75, 76, 79, 82, 83, 84, 86, 88, 89, 90, 91, 96, 98, 99, 100, 101, 103, 104, 105, 106, 107, 108

Offset

1,1

Links

Table of n, a(n) for n=1..68.

Example

1, 3, 6 and 7 occur twice in A005229, so these numbers are not in the sequence.

Mathematica

terms = 70; Clear[b, f]; b[1] = b[2] = 1; b[n_] := b[n] = b[b[n - 2]] + b[n - b[n - 2]]; f[max_] := f[max] = PadRight[Select[Tally[Array[b, max]], #[[2]] == 1 &][[All, 1]], terms]; f[max = terms]; f[max = max + terms]; While[f[max] != f[max - terms], max = max + terms]; A118179 = f[max](* Jean-François Alcover, Oct 12 2017 *)

Prog

(PARI) {m=156; v=vector(m); v[1]=1; v[2]=1; for(n=3, m, v[n]=v[v[n-2]]+v[n-v[n-2]]); i=1; k=1; while(i<=m, c=0; while(i<=m&&v[i]==k, c++; i++); if(i<=m&&c==1, print1(k, ", ")); k++)}

Crossrefs

Cf. A005229, A087758, A088359.

Sequence in context: A117121 A101925 A101884 * A096603 A084464 A289008

Adjacent sequences: A118176 A118177 A118178 * A118180 A118181 A118182

Keyword

nonn

Author

Klaus Brockhaus, Apr 13 2006

Status

approved