OFFSET
1,1
LINKS
Michael S. Branicky, Table of n, a(n) for n = 1..441 (terms 1..100 from Harvey P. Dale)
MATHEMATICA
a[1] = 6; a[n_] := a[n] = Block[{k = a[n - 1], c = IntegerDigits @ Table[ a[i], {i, n - 1}]}, While[ !PrimeQ[ FromDigits @ Flatten @ Append[c, IntegerDigits[k]]], k ++ ]; k]; Table[ a[n], {n, 47}] (* Robert G. Wilson v, Aug 05 2005 *)
nxt[{j_, a_}]:=Module[{k=a}, While[!PrimeQ[j*10^IntegerLength[k]+k], k++]; {j*10^IntegerLength[k]+k, k}]; Transpose[NestList[nxt, {6, 6}, 50]][[2]] (* Harvey P. Dale, May 07 2016 *)
PROG
(Python)
from sympy import isprime
def aupton(terms):
alst, astr = [6], "6"
for n in range(2, terms+1):
an = alst[-1]
while not isprime(int(astr+str(an))): an += 1
alst, astr = alst + [an], astr + str(an)
return alst
print(aupton(62)) # Michael S. Branicky, Jun 07 2021
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Patrick De Geest, May 15 1998
STATUS
approved