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A359777
Numbers k such that A356163(k) = 1 but A359774(k) = 0, where A359774 is the parity of Dirichlet inverse of the former (which is the characteristic function of the numbers with an even sum of prime factors, with repetition).
4
4, 8, 16, 32, 36, 60, 64, 72, 81, 84, 100, 120, 128, 132, 140, 144, 156, 162, 168, 196, 200, 204, 220, 225, 228, 240, 256, 260, 264, 276, 280, 288, 308, 312, 324, 336, 340, 348, 364, 372, 380, 392, 400, 408, 440, 441, 444, 450, 456, 460, 476, 480, 484, 492, 512, 516, 520, 528, 532, 540, 552, 560, 564
OFFSET
1,1
FORMULA
{k | A356163(k)-A359774(k) == 1}.
PROG
(PARI)
A356163(n) = (1-(((n=factor(n))[, 1]~*n[, 2])%2)); \\ After code in A001414.
memoA359773 = Map();
A359773(n) = if(1==n, 1, my(v); if(mapisdefined(memoA359773, n, &v), v, v = -sumdiv(n, d, if(d<n, A356163(n/d)*A359773(d), 0)); mapput(memoA359773, n, v); (v)));
A359774(n) = (A359773(n)%2);
isA359767(n) = (A356163(n)&&!(A359774(n)));
CROSSREFS
Setwise difference A036349 \ A359775.
Setwise difference A359776 \ A335657.
Cf. also A359767, A359784.
Sequence in context: A125626 A141031 A061011 * A181800 A319180 A075090
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jan 15 2023
STATUS
approved