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A352092
Starts of runs of 4 consecutive tribonacci-Niven numbers (A352089).
11
1602, 218349, 296469, 1213749, 1291869, 1896630, 1952070, 2153709, 2399550, 3149109, 3753870, 3809310, 3983229, 4226208, 4256790, 4449288, 4711482, 5707897, 5727708, 6141750, 6589230, 6969429, 7205757, 7229208, 7276143, 7292943, 7454710, 7752588, 7937109, 8877069
OFFSET
1,1
COMMENTS
Conjecture: There are no runs of 5 consecutive tribonacci-Niven numbers (checked up to 10^10).
LINKS
EXAMPLE
1602 is a term since 1602, 1603, 1604 and 1605 are all divisible by the number of terms in their minimal tribonacci representation:
k A278038(k) A278043(k) k/A278043(k)
--------------------------------------------
1602 110100011010 6 267
1603 110100011011 7 229
1604 110100100000 4 401
1605 110100100001 5 321
MATHEMATICA
t[1] = 1; t[2] = 2; t[3] = 4; t[n_] := t[n] = t[n - 1] + t[n - 2] + t[n - 3]; triboNivenQ[n_] := Module[{s = {}, m = n, k}, While[m > 0, k = 1; While[t[k] <= m, k++]; k--; AppendTo[s, k]; m -= t[k]; k = 1]; Divisible[n, DigitCount[Total[2^(s - 1)], 2, 1]]]; seq[count_, nConsec_] := Module[{tri = triboNivenQ /@ Range[nConsec], s = {}, c = 0, k = nConsec + 1}, While[c < count, If[And @@ tri, c++; AppendTo[s, k - nConsec]]; tri = Join[Rest[tri], {triboNivenQ[k]}]; k++]; s]; seq[6, 4]
CROSSREFS
Subsequence of A352089, A352090 and A352091.
Sequence in context: A031538 A202774 A293370 * A252439 A224949 A171466
KEYWORD
nonn,base
AUTHOR
Amiram Eldar, Mar 04 2022
STATUS
approved