A329481 Numbers which are not the sum of two squarefree semiprimes.

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 14, 15, 17, 18, 19, 22, 23, 26, 33, 34, 38, 46, 51, 58, 62, 82

Offset

1,3

Comments

Is this a finite sequence?

Most probably yes. Since almost all semiprimes are squarefree, this is essentially the same as A072966. The graph of A072931 would not change qualitatively if only squarefree semiprimes were considered. - M. F. Hasler, Dec 03 2019

Links

Table of n, a(n) for n=1..29.

Example

a(10) = 11 since there is no way to represent 11 as a sum of two squarefree semiprimes. 12 is not a term since 12 = 6 + 6.

Crossrefs

Cf. A006881, A072966.

Sequence in context: A191328 A064683 A317468 * A261355 A084384 A119885

Adjacent sequences: A329478 A329479 A329480 * A329482 A329483 A329484

Keyword

nonn

Author

Lior Manor, Nov 14 2019

Status

approved