login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A024782 Every suffix prime and no 0 digits in base 7 (written in base 7). 7
2, 3, 5, 23, 25, 32, 43, 52, 65, 443, 452, 623, 625, 632, 652, 2452, 2623, 6625, 6652, 42623, 642623, 6642623 (list; graph; refs; listen; history; text; internal format)
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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 17 16:12 EDT 2022. Contains 353747 sequences. (Running on oeis4.)