OFFSET
1,1
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..200
EXAMPLE
The first prime > 235, the concatenation of the first three primes, is 239. Hence a(3) = 239.
MATHEMATICA
p[n_] := Module[{r, i}, r = 2; i = 1; While[r <= n, i = i + 1; r = Prime[i]]; r]; s = ""; a = {}; Do[s = s <> ToString[Prime[i]]; a = Append[a, p[ToExpression[s]]], {i, 1, 8}]; a
<<NumberTheory`NumberTheoryFunctions` sz[x_] :=FromDigits[Flatten[Table[IntegerDigits[Prime[j]], {j, 1, x}], 1]] Table[NextPrime[sz[w]], {w, 1, 35}] (* Labos Elemer, Mar 18 2005 *)
Module[{nn=20, p}, p=Prime[Range[nn]]; Table[NextPrime[FromDigits[Flatten[ IntegerDigits/@Take[p, n]]]], {n, nn}]] (* Harvey P. Dale, Oct 03 2013 *)
PROG
(Python)
from sympy import nextprime, prime, primerange
def a(n):
return nextprime(int("".join(map(str, primerange(2, prime(n)+1)))))
print([a(n) for n in range(1, 17)]) # Michael S. Branicky, Mar 29 2021
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Joseph L. Pe, Sep 26 2002
EXTENSIONS
More terms from Labos Elemer, Mar 18 2005
Edited by N. J. A. Sloane, May 21 2008 at the suggestion of R. J. Mathar
Edited by Charles R Greathouse IV, Apr 28 2010
STATUS
approved