A333427 Numbers k such that k and k+1 are both primorial base Niven numbers (A333426).

1, 8, 24, 32, 44, 64, 65, 132, 212, 224, 244, 245, 296, 368, 424, 425, 468, 560, 656, 720, 728, 737, 869, 1056, 1088, 1416, 1572, 1728, 2100, 2312, 2324, 2344, 2345, 2524, 2525, 2568, 2600, 2672, 2820, 2960, 3032, 3132, 3156, 3200, 3288, 3392, 3444, 4096, 4424

Offset

1,2

Links

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

Example

1 is a term since 1 and 2 are both primorial base Niven numbers.

Mathematica

max = 6; bases = Prime @ Range[max, 1, -1]; nmax = Times @@ bases - 1; primNivenQ[n_] := Divisible[n, Plus @@ IntegerDigits[n, MixedRadix[bases]]]; q1 = primNivenQ[1]; seq = {}; Do[q2 = primNivenQ[n]; If[q1 && q2, AppendTo[seq, n - 1]]; q1 = q2, {n, 2, nmax}]; seq

Crossrefs

Cf. A328205, A328209, A328213, A330927, A330931, A333426.

Sequence in context: A056196 A044069 A028628 * A128690 A283078 A319528

Adjacent sequences: A333424 A333425 A333426 * A333428 A333429 A333430

Keyword

nonn

Author

Amiram Eldar, Mar 20 2020

Status

approved