A321517 Numbers k such that A294902(k) != A321516(k).

50, 75, 100, 125, 150, 175, 190, 200, 222, 225, 238, 242, 246, 250, 275, 285, 300, 325, 333, 338, 350, 357, 363, 369, 374, 375, 380, 400, 425, 438, 442, 444, 450, 475, 476, 484, 492, 494, 500, 507, 525, 550, 555, 561, 570, 575, 578, 595, 600, 605, 615, 625

Offset: 1

Author

Felix Fröhlich, Nov 12 2018

Keywords

• nonn

Crossrefs

Cf. A033942, A294902, A321516.

Programs

Mathematica

A321516[n_] := Length[Select[Most[Divisors[n]], CompositeQ]]; abQ[n_] := DivisorSum[n, Total[IntegerDigits[#, 2]]*(-1)^Boole[#==n]&]>0; A294902[n_] := Length[Select[Most[Divisors[n]], abQ[#] &]]; Select[Range[650], A321516[#] != A294902 [#] &] (* Amiram Eldar, Nov 12 2018 after Jean-François Alcover at A175526 *)

PARI

a292257(n) = sumdiv(n, d, (dAntti Karttunen in A292257
a294905(n) = (a292257(n) <= hammingweight(n)) \\ after Antti Karttunen in A294905
a294902(n) = sumdiv(n, d, (dAntti Karttunen in A294902
a321516(n) = my(d=divisors(n), i=0); for(k=2, #d-1, if(!ispseudoprime(d[k]), i++)); i
is(n) = a294902(n)!=a321516(n)