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A104423
Numbers n such that n, p[n], p[n]+n, p[n]-n and p[n]*n all are 3-less.
2
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
1,1
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.
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]=={}&]
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Zak Seidov, Mar 07 2005
STATUS
approved