OFFSET
1,2
COMMENTS
Prime(n) is all 0's followed by prime(n). a(n) is all 4's followed by prime(n). Conjecture: No term is zero for n > 3.
a(346) = 0 or a(346) > 5000, but note a(892) = 3612. - D. S. McNeil, Feb 04 2011
EXAMPLE
a(7) = 44417, as prime(7) = 17 and both 417 and 4417 are composite.
MATHEMATICA
Table[If[n==1||n==3, 0, Select[FromDigits/@(Join[#, IntegerDigits[Prime[n]]]& /@ (Table[PadLeft[{4}, k, 4], {k, 50}])), PrimeQ, 1][[1]]], {n, 35}] (* Harvey P. Dale, Feb 03 2011 *)
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Amarnath Murthy, Nov 17 2005
EXTENSIONS
More terms from Joshua Zucker, May 06 2006
Edited by Jon E. Schoenfield, May 19 2019
STATUS
approved