OFFSET
1,1
EXAMPLE
23 is prime, 2 < 3, and 2 + 23 = 25 (composite) = a(9);
29 is prime, 2 < 9, and 2 + 29 = 31 (prime);
31 is prime, 3 > 1, and 1 + 31 = 32 (composite) = a(10); etc.
MAPLE
A054054 := proc(n) min(op(convert(n, base, 10)) ) ; end proc: A144592 := proc(n) p := ithprime(n) ; sd := A054054(p) ; if not isprime(p+sd) then printf("%d, ", p+sd) ; end if; end proc: seq(A144592(n), n=1..400) ; # R. J. Mathar, May 01 2010
MATHEMATICA
Select[#+Min[IntegerDigits[#]]&/@Prime[Range[100]], CompositeQ] (* Harvey P. Dale, Jun 28 2015 *)
PROG
(PARI) for(n=1, 1e3, if(isprime(k=if(n, vecmin(digits(prime(n)))) + prime(n)) == 0, print1(k", "))) \\ Altug Alkan, Oct 17 2015
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Juri-Stepan Gerasimov, Jan 12 2009
EXTENSIONS
Sequence corrected (by adding 235, which had erroneously been omitted) by Harvey P. Dale, Feb 08 2009
STATUS
approved