A024781 Every suffix prime and no 0 digits in base 6 (written in base 6).

2, 3, 5, 15, 25, 35, 45, 115, 125, 135, 215, 225, 245, 335, 345, 435, 445, 515, 525, 1115, 1125, 1245, 1335, 1345, 1435, 1445, 2115, 2135, 2225, 2335, 2345, 2435, 3125, 3445, 3515, 4115, 4215, 4225, 4435, 4525, 5215, 5245, 5345, 5525, 11115, 11245, 12135

Offset: 1

Author

David W. Wilson

Keywords

• nonn
• base
• easy
• fini
• full

Comments

The final term is a(454) = 14141511414451435.

Links

• Nathaniel Johnston, Table of n, a(n) for n = 1..454 (full sequence)

Crossrefs

Cf. A024779, A024780, A024781, A024782, A024783, A024784, A024785

Programs

Maple

a:=[[2], [3], [5]]: b:=[]: l1:=1: l2:=5: do for j from l1 to l2 do for k from 1 to 5 do d:=[op(a[j]),k]: if(isprime(op(convert(d, base, 6, 6^nops(d)))))then a:=[op(a), d]: fi: od: od: l1:=l2+1: l2:=nops(a): if(l1>l2)then break: fi: od: for j from 1 to nops(a) do b:=[op(b),op(convert(a[j], base, 10, 10^nops(a[j])))]: od: b:=sort(b): seq(b[j],j=1..nops(b)); # Nathaniel Johnston, Jun 21 2011

Python

from sympy import isprime
def afull():
    prime_strings, alst = list("235"), []
    while len(prime_strings) > 0:
        alst.extend(sorted(int(p) for p in prime_strings))
        candidates = set(d+p for p in prime_strings for d in "12345")
        prime_strings = [c for c in candidates if isprime(int(c, 6))]
    return alst
print(afull()) # Michael S. Branicky, Apr 27 2022