A053582 a(n+1) is the smallest prime ending with a(n), where a(1)=1.

1, 11, 211, 4211, 34211, 234211, 4234211, 154234211, 3154234211, 93154234211, 2093154234211, 42093154234211, 342093154234211, 11342093154234211, 3111342093154234211, 63111342093154234211, 2463111342093154234211, 232463111342093154234211

Offset

1,2

Links

Table of n, a(n) for n = 1..501

Example

The least prime ending with seed 1 is 11; the least prime ending with 11 is 211; the least prime ending with 211 is 4211. - Clark Kimberling, Sep 17 2015

Maple

R:= 1: v:= 1:
for iter from 1 to 30 do
d:= ilog10(v)+1;
for x from v+10^d by 10^d do
  if isprime(x) then R:= R, x; v:= x; break fi
od
od:
R; # Robert Israel, Sep 24 2020

Mathematica

f[n_] := f[n] = Block[{j = f[n - 1], k = 1, l = Floor[Log[10, f[n - 1]] + 1]},   While[m = k*10^l + j; ! PrimeQ@ m, k++ ]; m]; f[1] = 1; Array[f, 17]
nxt[n_]:=Module[{k=1, p=10^IntegerLength[n]}, While[!PrimeQ[k*p+n], k++]; k*p+n]; NestList[nxt, 1, 20] (* Harvey P. Dale, Jul 14 2016 *)

Prog

(Python)
from sympy import isprime
from itertools import count, islice
def agen(an=1): # generator of terms
    while True:
        yield an
        pow10 = 10**len(str(an))
        for t in count(pow10+an, step=pow10):
            if isprime(t):
                an = t
                break
print(list(islice(agen(), 18))) # Michael S. Branicky, Jun 23 2022

Crossrefs

Cf. A053583, A053584, A069612.

Sequence in context: A249604 A038399 A053547 * A077714 A089567 A372075

Adjacent sequences: A053579 A053580 A053581 * A053583 A053584 A053585

Keyword

base,nonn

Author

G. L. Honaker, Jr., Jan 18 2000

Extensions

a(14)-a(17) corrected by Robert G. Wilson v, Dec 07 2010

Status

approved