1,4

Also A025582(n) - A010672(n-1).

A005282 is the sequence of smallest numbers such that the pairwise sums of not necessarily distinct elements are all distinct, whereas A011185 is the sequence of smallest numbers such that the pairwise sums of distinct elements are all distinct.

Sequence has negative terms; the first one is a(65) = -130.

K. Brockhaus, Table of n, a(n) for n = 1..2400

a(6) = A005282(6) - A011185(6) = 21 - 13 = 8.

Cf. A005282, A011185, A025582, A010672, A133096.

Sequence in context: A088937 A123327 A117467 this_sequence A117176 A127700 A101907

Adjacent sequences: A133094 A133095 A133096 this_sequence A133098 A133099 A133100

nonn

Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Sep 17 2007