OFFSET
1,1
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..363 (all terms up to 10 million)
EXAMPLE
33 is a term: remove any digit to be left with 3. Subtract 1 gives 2, which is prime.
4444 is a term: remove any digit to be left with 444. Subtract 1 to be left with 443, which is prime.
28 is not a term: remove any digit to be left with 2 or 8. Subtract 1 to be left with 1 or 7. 1 is not prime.
MAPLE
q:= n-> (s-> andmap(i-> isprime(parse(cat(0, s[1..i-1],
s[i+1..-1]))-1), [$1..length(s)]))(""||n):
select(q, [$1..5000])[]; # Alois P. Heinz, May 30 2020
MATHEMATICA
rdpQ[x_]:=AllTrue[FromDigits/@Table[Drop[IntegerDigits[x], {n}], {n, IntegerLength[ x]}]-1, PrimeQ]; Select[Range[4700], rdpQ] (* Harvey P. Dale, Aug 21 2020 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
John Ryder, May 30 2020
STATUS
approved