OFFSET
1,1
COMMENTS
Any term of this sequence has one prime digit and all other digits are 1. - Sean A. Irvine, Apr 17 2021
REFERENCES
James J. Tattersall, Elementary Number Theory in Nine Chapters, Cambridge University Press, 1999, page 113.
LINKS
Alois P. Heinz, Table of n, a(n) for n = 1..1000
MATHEMATICA
d[n_]:=IntegerDigits[n]; t={}; Do[p=Prime[n]; If[PrimeQ[Plus@@(x=d[p])]&&PrimeQ[Times@@x], AppendTo[t, p]], {n, 2*10^5}]; t (* Jayanta Basu, May 18 2013 *)
Select[Prime[Range[5033*10^5]], AllTrue[{Total[IntegerDigits[ #]], Times@@ IntegerDigits[ #]}, PrimeQ]&] (* or -- much faster *) Select[Union[ Flatten[ Table[FromDigits/@Permutations[PadRight[{p}, n, 1]], {p, {2, 3, 5, 7}}, {n, 11}]]], AllTrue[{#, Total[ IntegerDigits[#]], Times@@ IntegerDigits[ #]}, PrimeQ]&] (* Harvey P. Dale, Feb 28 2022 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
EXTENSIONS
More terms from Harvey P. Dale, Aug 23 2000
Corrected by Jud McCranie, Jan 03 2001
Edited by Charles R Greathouse IV, Aug 02 2010
STATUS
approved
