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A324335
a(n) = A323363(A005940(1+n)), where A005940 is the Doudna sequence and A323363 is the Dirichlet inverse of Dedekind's psi.
6
1, -3, -4, 3, -6, 12, 4, -3, -8, 18, 24, -12, 6, -12, -4, 3, -12, 24, 32, -18, 48, -72, -24, 12, 8, -18, -24, 12, -6, 12, 4, -3, -14, 36, 48, -24, 72, -96, -32, 18, 96, -144, -192, 72, -48, 72, 24, -12, 12, -24, -32, 18, -48, 72, 24, -12, -8, 18, 24, -12, 6, -12, -4, 3, -18, 42, 56, -36, 84, -144, -48, 24, 112, -216, -288, 96, -72, 96, 32, -18
OFFSET
0,2
FORMULA
a(n) = A323363(A005940(1+n)).
PROG
(PARI)
A005940(n) = { my(p=2, t=1); n--; until(!n\=2, if((n%2), (t*=p), p=nextprime(p+1))); t }; \\ From A005940
A001615(n) = (n * sumdivmult(n, d, issquarefree(d)/d)); \\ From A001615
memoA323363 = Map();
A323363(n) = if(1==n, 1, my(v); if(mapisdefined(memoA323363, n, &v), v, v = -sumdiv(n, d, if(d<n, A001615(n/d)*A323363(d), 0)); mapput(memoA323363, n, v); (v)));
A324335(n) = A323363(A005940(1+n));
CROSSREFS
KEYWORD
sign
AUTHOR
Antti Karttunen, Feb 23 2019
STATUS
approved