A121175 Sequence S with the following properties: (i) a(1)=2; (ii) for n is S, a(n)=a(1)+a(2)+...+a(n-1); (iii) for n not in S, a(n)=the smallest number different from a(1), ..., a(n-1) not breaking property (ii).

2, 2, 4, 8, 3, 7, 26, 52, 10, 114, 12, 240, 14, 494, 16, 1004, 18, 2026, 20, 4072, 22, 8166, 24, 16356, 27, 32739, 65478, 29, 130985, 31, 262001, 33, 524035, 35, 1048105, 37, 2096247, 39, 4192533, 41, 8385107, 43, 16770257, 45, 33540559

Offset

1,1

Comments

Taking a(1)=2 makes all terms distinct except for a(1)=a(2)=2

Links

Table of n, a(n) for n=1..45.

Crossrefs

Cf. A105753, A121053, A121174, A121173.

Sequence in context: A093094 A045777 A136534 * A368515 A366714 A359488

Adjacent sequences: A121172 A121173 A121174 * A121176 A121177 A121178

Keyword

nonn

Author

Max Alekseyev, Aug 15 2006

Status

approved