A024782 Every suffix prime and no 0 digits in base 7 (written in base 7).

2, 3, 5, 23, 25, 32, 43, 52, 65, 443, 452, 623, 625, 632, 652, 2452, 2623, 6625, 6652, 42623, 642623, 6642623

Offset

1,1

Links

Table of n, a(n) for n=1..22.

Maple

a:=[[2], [3], [5]]: b:=[]: l1:=1: l2:=3: do for k from 1 to 6 do for j from l1 to l2 do d:=[op(a[j]), k]: if(isprime(op(convert(d, base, 7, 7^nops(d)))))then a:=[op(a), d]: fi: od: od: l1:=l2+1: l2:=nops(a): if(l1>l2)then break: fi: od: seq(op(convert(a[j], base, 10, 10^nops(a[j]))), j=1..nops(a)); # Nathaniel Johnston, Jun 21 2011

Prog

(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 "123456")
        prime_strings = [c for c in candidates if isprime(int(c, 7))]
    return alst
print(afull()) # Michael S. Branicky, Apr 27 2022

Crossrefs

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

Sequence in context: A047995 A244862 A338403 * A024775 A024767 A041195

Adjacent sequences: A024779 A024780 A024781 * A024783 A024784 A024785

Keyword

nonn,easy,base,fini,full

Author

David W. Wilson

Status

approved