A104428 Numbers n such that n, p[n], p[n]+n, p[n]-n and p[n]*n all are 8-less.

1, 2, 5, 7, 9, 10, 11, 12, 14, 15, 17, 20, 21, 25, 26, 32, 33, 34, 40, 46, 50, 54, 55, 57, 63, 64, 70, 73, 74, 90, 95, 97, 99, 100, 104, 105, 110, 113, 114, 115, 116, 117, 119, 137, 156, 191, 192, 200, 203, 204, 213, 220, 225, 226, 227, 240, 244, 261, 262, 264, 265

Offset

1,2

Comments

From the first 3000 primes, only 356 are such that n, p[n], p[n]+n, p[n]-n and p[n]*n all are 8-less.

Links

Table of n, a(n) for n=1..61.

Mathematica

id[x_]:=IntegerDigits[x]; pr[i_]:=Prime[i]; ra=Range[3000]; A104428=Select[ra, Position[Union[id[ # ], id[pr[ # ]], id[pr[ # ]+# ], id[pr[ # ]-# ], id[pr[ # ]*# ]], 8]=={}&]

Crossrefs

Cf. A104419-A104428.

Sequence in context: A070985 A325431 A246339 * A349830 A241884 A291109

Adjacent sequences: A104425 A104426 A104427 * A104429 A104430 A104431

Keyword

nonn,base

Author

Zak Seidov, Mar 07 2005

Status

approved