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A117959 Perrin numbers which are divisible by their digital root.

%I A117959 #10 Mar 17 2023 05:51:14
%S A117959 2,3,5,7,10,12,39,90,486,1130,1497,1983,3480,4610,10717,24914,33004,
%T A117959 57918,76725,134643,178364,549289,727653,1691588,2240877,2968530,
%U A117959 3932465,5209407,12110402,28153269,65448410,86700684,114853953,1089264462,1911525877,3354494070
%N A117959 Perrin numbers which are divisible by their digital root.
%H A117959 Robert Israel, <a href="/A117959/b117959.txt">Table of n, a(n) for n = 1..3698</a>
%e A117959 1130 is in the sequence because (1) it is a Perrin number, (2) the digital root is 5 and (3) 1130 is divisible by 5.
%p A117959 R:= NULL: count:= 0:
%p A117959 a:= 3: b:= 0: c:= 2:
%p A117959 while count < 100 do
%p A117959   q:= a+b;
%p A117959   a:= b; b:= c; c:= q;
%p A117959   dr:= c mod 9; if dr = 0 then dr:= 9 fi;
%p A117959   if c mod dr = 0 then R:= R,c; count:= count+1;
%p A117959   fi
%p A117959 od:
%p A117959 sort(convert({R},list)); # _Robert Israel_, Mar 16 2023
%t A117959 Select[Union @ LinearRecurrence[{0, 1, 1}, {2, 3, 2}, 100], Divisible[#, Mod[# - 1, 9] + 1] &] (* _Amiram Eldar_, Feb 06 2021 *)
%Y A117959 Intersection of A001608 and A064807.
%Y A117959 Cf. A010888.
%K A117959 base,nonn
%O A117959 1,1
%A A117959 Luc Stevens (lms022(AT)yahoo.com), May 03 2006
%E A117959 Data corrected by _Amiram Eldar_, Feb 06 2021