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A342427
Numbers k such that k and k + 1 are both Niven numbers in base 3/2 (A342426).
16
1, 168, 459, 1817, 2196, 2197, 2655, 3128, 3280, 3699, 4199, 4575, 4927, 5184, 5795, 6600, 7215, 7259, 7656, 7657, 8448, 9636, 11304, 11339, 12492, 14160, 14175, 14424, 14805, 15624, 15625, 16335, 16336, 16925, 17802, 19170, 20349, 20811, 21624, 21735, 22197
OFFSET
1,2
LINKS
EXAMPLE
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.
MATHEMATICA
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] &]
CROSSREFS
Subsequence of A342426.
Subsequences: A342428 and A342429.
Similar sequences: A330927 (decimal), A328205 (factorial), A328209 (Zeckendorf), A328213 (lazy Fibonacci), A330931 (binary), A331086 (negaFibonacci), A333427 (primorial), A334309 (base phi), A331820 (negabinary).
Sequence in context: A210207 A303082 A247721 * A027679 A137863 A266808
KEYWORD
nonn,base
AUTHOR
Amiram Eldar, Mar 11 2021
STATUS
approved