A363791 Starts of runs of 3 consecutive integers that are primitive binary Niven numbers (A363787).

4184046, 5234670, 6285294, 7861230, 8123886, 8255214, 8255215, 8320878, 8353710, 8370126, 8379247, 12238830, 12451631, 12572622, 13623246, 13629935, 14515182, 14646510, 14673870, 14673871, 14679342, 15040494, 15335375, 15449071, 15531759, 15708078, 15986543, 16178670

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Example

4184046 is a term since 4184046, 4184047 and 4184048 are all primitive binary Niven numbers.

Mathematica

binNivQ[n_] := Divisible[n, DigitCount[n, 2, 1]]; primBinNivQ[n_] := binNivQ[n] && ! (EvenQ[n] && binNivQ[n/2]);
seq[kmax_] := Module[{tri = primBinNivQ /@ Range[3], s = {}, k = 4}, While[k < kmax, If[And @@ tri, AppendTo[s, k - 3]]; tri = Join[Rest[tri], {primBinNivQ[k]}]; k++]; s]; seq[10^7]

Prog

(PARI) isbinniv(n) = !(n % hammingweight(n));
isprim(n) = isbinniv(n) && !(!(n%2) && isbinniv(n/2));
lista(kmax) = {my(tri = vector(3, i, isprim(i)), k = 4); while(k < kmax, if(vecsum(tri) == 3, print1(k-3, ", ")); tri = concat(vecextract(tri, "^1"), isprim(k)); k++); }

Crossrefs

Subsequence of A049445, A330931, A330932, A363787 and A363790.

A363792 is a subsequence.

Sequence in context: A251371 A234232 A140968 * A251496 A011572 A022538

Adjacent sequences: A363788 A363789 A363790 * A363792 A363793 A363794

Keyword

nonn,base

Author

Amiram Eldar, Jun 22 2023

Status

approved