A104423 Numbers n such that n, p[n], p[n]+n, p[n]-n and p[n]*n all are 3-less.

5, 7, 8, 20, 25, 26, 45, 47, 50, 95, 100, 101, 102, 105, 107, 109, 110, 121, 145, 149, 155, 156, 158, 160, 161, 165, 167, 168, 169, 171, 177, 180, 181, 205, 209, 210, 271, 272, 275, 277, 279, 284, 288, 290, 292, 297, 299, 628, 629, 745, 751, 761, 764, 765, 769

Offset: 1

Author

Zak Seidov, Mar 07 2005

Keywords

• nonn
• base

Comments

From the first 3000 primes, only 200 are such that n, p[n], p[n]+n, p[n]-n and p[n]*n all are 3-less.

Crossrefs

Cf. A104419-A104428.

Programs

Mathematica

id[x_]:=IntegerDigits[x];pr[i_]:=Prime[i];ra=Range[3000];A104423=Select[ra, Position[Union[id[ # ], id[pr[ # ]], id[pr[ # ]+# ], id[pr[ # ]-# ], id[pr[ # ]*# ]], 3]=={}&]