A024784 Every suffix prime and no 0 digits in base 9 (written in base 9).

2, 3, 5, 7, 12, 25, 32, 45, 47, 52, 65, 67, 87, 212, 232, 267, 287, 425, 432, 447, 465, 625, 667, 812, 832, 847, 867, 887, 2287, 2432, 4212, 4465, 4667, 4832, 4847, 4887, 6212, 6267, 6425, 6832, 6887, 8287, 8447, 8667, 8812, 22287, 24465, 24847, 26212, 26887

Offset

1,1

Comments

The final term of the sequence is a(108) = 4284484465.

Links

Nathaniel Johnston, Table of n, a(n) for n = 1..108 (full sequence)

Maple

a:=[[2], [3], [5], [7]]: l1:=1: l2:=4: do for k from 1 to 8 do for j from l1 to l2 do d:=[op(a[j]), k]: if(isprime(op(convert(d, base, 9, 9^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():
    prime9strings, alst = list("2357"), []
    while len(prime9strings) > 0:
        alst.extend(sorted(int(p) for p in prime9strings))
        candidates = set(d+p for p in prime9strings for d in "12345678")
        prime9strings = [c for c in candidates if isprime(int(c, 9))]
    return alst
print(afull()) # Michael S. Branicky, Apr 27 2022

Crossrefs

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

Sequence in context: A344454 A235153 A177968 * A060528 A273728 A117593

Adjacent sequences: A024781 A024782 A024783 * A024785 A024786 A024787

Keyword

nonn,base,easy,fini,full

Author

David W. Wilson

Status

approved