|
%I #5 Mar 09 2018 17:12:13
%S 5,6,16,18,30,36,78,81,83,90,94,95,100,103,104,105,108,110,111,114,
%T 131,133,136,137,139,153,154,159,160,166,488,489,495,496,498,499,500,
%U 510,511,514,640,641,643,644,645,646,650,665,669,671,680,685,687,688,690
%N Numbers n such that n, p[n], p[n]+n, p[n]-n and p[n]*n all are 2-less.
%C From the first 3000 primes, only 182 are such that n, p[n], p[n]+n, p[n]-n and p[n]*n all are 2-less.
%H Harvey P. Dale, <a href="/A104422/b104422.txt">Table of n, a(n) for n = 1..1000</a>
%t id[x_]:=IntegerDigits[x];pr[i_]:=Prime[i];ra=Range[3000];A104422=Select[ra, Position[Union[id[ # ], id[pr[ # ]], id[pr[ # ]+# ], id[pr[ # ]-# ], id[pr[ # ]*# ]], 2]=={}&]
%t tlQ[n_]:=DigitCount[n,10,2]==0; Select[Range[700],AllTrue[{#,p=Prime[#], p+#,p-#,p*#},tlQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* _Harvey P. Dale_, Mar 09 2018 *)
%Y Cf. A104419-A104428.
%K nonn,base
%O 1,1
%A _Zak Seidov_, Mar 07 2005
|
