A027563 Numbers not of form abc + abd + acd + bcd for 1<=a<=b<=c<=d.

1, 2, 3, 5, 6, 8, 9, 11, 14, 15, 18, 21, 23, 26, 29, 30, 33, 35, 41, 48, 51, 53, 63, 65, 74, 75, 86, 89, 90, 98, 111, 113, 119, 125, 131, 141, 155, 158, 173, 179, 191, 209, 210, 233, 239, 251, 254, 273, 285, 293, 321, 323, 326, 338, 341, 345, 363, 419

Offset: 1

Author

R. H. Hardin

Keywords

• nonn
• fini
• full

Comments

This list is conjecturally complete, but this has not been proved. It may be complete as a consequence of the Generalized Riemann Hypothesis; see comments for A025052. - Harry Richman, Jan 09 2025

Links

• T. D. Noe, Table of n, a(n) for n=1..126 (complete sequence)

Crossrefs

Cf. A025052 (3 variables), A027564 (5 variables), A027565, A027566.