A368406 Numbers k such that A368405(k) = 0.

2, 22, 28, 34, 42, 44, 110, 114, 140, 198, 202, 204, 376, 380, 500, 646, 690, 692, 694, 840, 842, 856, 858, 866, 868, 876, 878, 880, 896, 898, 900, 902, 910, 914, 916, 1036, 1038, 1042, 1044, 1046, 1048, 1050, 1052, 1054, 1066, 1068, 1076, 1078, 1080, 1088, 1090

Offset: 1

Author

Amiram Eldar, Dec 23 2023

Keywords

• nonn
• easy

Links

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

Crossrefs

Cf. A028442, A275547, A368405.

Programs

Mathematica

f[p_, e_] := (-1)^DigitCount[e, 2, 1]; imu[1] = 1; imu[n_] := Times @@ f @@@ FactorInteger[n]; Position[Accumulate[Array[imu, 1000]], 0] // Flatten

PARI

imu(n) = vecprod(apply(x -> (-1)^hammingweight(x), factor(n)[, 2]));
lista(n) = {my(s = 0); for(k = 1, n, s+ = imu(k); if(s == 0, print1(k, ", ")));}