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A342427 Numbers k such that k and k + 1 are both Niven numbers in base 3/2 (A342426). 5

%I

%S 1,168,459,1817,2196,2197,2655,3128,3280,3699,4199,4575,4927,5184,

%T 5795,6600,7215,7259,7656,7657,8448,9636,11304,11339,12492,14160,

%U 14175,14424,14805,15624,15625,16335,16336,16925,17802,19170,20349,20811,21624,21735,22197

%N Numbers k such that k and k + 1 are both Niven numbers in base 3/2 (A342426).

%H Amiram Eldar, <a href="/A342427/b342427.txt">Table of n, a(n) for n = 1..10000</a>

%e 168 is a term since both 168 and 169 are Niven numbers in base 3/2. 168 in base 3/2 is 2120220210 and 2+1+2+0+2+2+0+2+1+0 = 12 is a divisor of 168. 169 in base 3/2 is 2120220211 and 2+1+2+0+2+2+0+2+1+1 = 13 is a divisor of 169.

%t s[0] = 0; s[n_] := s[n] = s[2*Floor[n/3]] + Mod[n, 3]; q[n_] := Divisible[n, s[n]]; Select[Range[22000], q[#] && q[# + 1] &]

%Y Subsequence of A342426.

%Y Subsequences: A342428 and A342429.

%Y Similar sequences: A330927 (decimal), A328205 (factorial), A328209 (Zeckendorf), A328213 (lazy Fibonacci), A330931 (binary), A331086 (negaFibonacci), A333427 (primorial), A334309 (base phi), A331820 (negabinary).

%K nonn,base

%O 1,2

%A _Amiram Eldar_, Mar 11 2021

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Last modified August 5 18:22 EDT 2021. Contains 346488 sequences. (Running on oeis4.)