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A256875 Numbers divisible by prime(d) for each digit d in their base-5 representation, none of which may be zero. 3

%I #16 Apr 05 2024 00:39:19

%S 6,12,36,156,162,186,282,306,312,546,784,786,906,912,924,936,1246,

%T 1536,1806,2674,2814,2856,3906,3912,3936,4032,4056,4062,4074,4284,

%U 4536,4656,4662,4686,4746,4914,5796,5922,6174,7032,7056,7062,7182,7434,7656,7662,7686,7782,7806,7812,8064,8106,8946,9072,9114,9282,9324

%N Numbers divisible by prime(d) for each digit d in their base-5 representation, none of which may be zero.

%C Base-5 analog of A256786. See A256874 - A256879 for the base-3, ..., base-9 analogs.

%C See A256865 for a variant where divisibility by prime(d+1) is required instead.

%C From _Robert Israel_, Apr 04 2024: (Start)

%C Since digit 0 is not allowed, terms can't be divisible by 5, so digit 3 is also not allowed.

%C All terms are even. (End)

%H Robert Israel, <a href="/A256875/b256875.txt">Table of n, a(n) for n = 1..10000</a>

%p P:= [seq(ithprime(i),i=1..4)]:

%p filter:= proc(n) local S,s;

%p S:= convert(convert(n,base,5),set);

%p if member(0,S) then return false fi;

%p n mod mul(P[s],s=S) = 0

%p end proc:

%p select(filter, [$1..10^4]); # _Robert Israel_, Apr 04 2024

%o (PARI) is(n,b=5)=!for(i=1,#d=Set(digits(n,b)),(!d[i]||n%prime(d[i]))&&return)

%Y Cf. A256786, A256874 - A256879, A256882 - A256884, A256865 - A256870.

%K nonn,base

%O 1,1

%A _M. F. Hasler_, Apr 11 2015

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Last modified April 25 01:06 EDT 2024. Contains 371964 sequences. (Running on oeis4.)