1,3

Is this sequence finite?

See the graph of sequence A072931 for compelling evidence that 33 is the last term of this sequence. - T. D. Noe, Apr 11 2007

Table of n, a(n) for n=1..13.

a(10) = 11 since there is no way to represent 11 as a sum of two semiprimes. 13 is not a term since 13 = 4 + 9.

Cf. A001358.

Sequence in context: A320318 A005577 A263362 * A245761 A059759 A042952

Adjacent sequences: A072963 A072964 A072965 * A072967 A072968 A072969

nonn,more

Lior Manor Aug 13 2002

approved