%I #15 Oct 13 2021 08:39:18

%S 10,13,23,49,111,113,171,211,293,309,309,469,639,759,951,1037,1057,

%T 1083,1257,1269,1287,1341,1551,1637,1677,1981,1989,2021,2059,2357,

%U 2583,2697,2967,3289,6789,7073,7323,7369,7463,7501,7709,7869,8029,8069,8077,8519

%N a(1) = 10; a(n) is smallest number >= a(n-1) such that the juxtaposition a(1)a(2)...a(n) is a prime.

%H Michael S. Branicky, <a href="/A111524/b111524.txt">Table of n, a(n) for n = 1..449</a>

%t a[1] = 10; a[n_] := a[n] = Block[{k = a[n - 1] + 1 + Mod[a[n - 1], 2], c = IntegerDigits @ Table[ a[i], {i, n - 1}]}, While[ !PrimeQ[ FromDigits @ Flatten @ Append[c, IntegerDigits[k]]], k += 2]; k]; Table[ a[n], {n, 46}] (* _Robert G. Wilson v_, Aug 05 2005 *)

%o (Python)

%o from sympy import isprime

%o def aupton(terms):

%o alst, astr = [10], "10"

%o while len(alst) < terms:

%o k = alst[-1] + (1 - alst[-1]%2)

%o while not isprime(int(astr+str(k))): k += 2

%o alst.append(k)

%o astr += str(k)

%o return alst

%o print(aupton(46)) # _Michael S. Branicky_, Oct 13 2021

%Y Cf. A111525, A074346, A033680, A033679, A033681.

%Y Cf. A046254, A046255, A046256, A046257, A046258, A046259.

%K base,nonn

%O 1,1

%A _Patrick De Geest_, _Zak Seidov_ and _Robert G. Wilson v_, Aug 05 2005