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

%I #14 Apr 27 2022 15:01:46

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

%T 42623,642623,6642623

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

%p 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

%o (Python)

%o from sympy import isprime

%o def afull():

%o prime_strings, alst = list("235"), []

%o while len(prime_strings) > 0:

%o alst.extend(sorted(int(p) for p in prime_strings))

%o candidates = set(d+p for p in prime_strings for d in "123456")

%o prime_strings = [c for c in candidates if isprime(int(c, 7))]

%o return alst

%o print(afull()) # _Michael S. Branicky_, Apr 27 2022

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

%K nonn,easy,base,fini,full

%O 1,1

%A _David W. Wilson_

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Last modified April 23 03:30 EDT 2024. Contains 371906 sequences. (Running on oeis4.)