login
A049851
Concatenate prevprime(n) and n.
1
23, 34, 35, 56, 57, 78, 79, 710, 711, 1112, 1113, 1314, 1315, 1316, 1317, 1718, 1719, 1920, 1921, 1922, 1923, 2324, 2325, 2326, 2327, 2328, 2329, 2930, 2931, 3132, 3133, 3134, 3135, 3136, 3137, 3738, 3739, 3740, 3741, 4142, 4143, 4344
OFFSET
3,1
LINKS
MATHEMATICA
Table[NextPrime[n, -1]*10^IntegerLength[n]+n, {n, 3, 50}] (* Harvey P. Dale, Aug 16 2024 *)
PROG
(PARI) a(n) = eval(concat(Str(precprime(n-1)), Str(n))); \\ Michel Marcus, Aug 11 2017
CROSSREFS
Cf. A151799.
Sequence in context: A145566 A146595 A230123 * A353087 A223606 A120147
KEYWORD
nonn,base
STATUS
approved