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A323411
Dirichlet inverse of A064664, the inverse permutation of EKG-sequence.
6
1, -2, -5, 1, -10, 16, -14, -4, 19, 31, -20, -21, -28, 43, 89, 4, -33, -98, -37, -42, 125, 61, -43, 48, 76, 85, -87, -58, -57, -409, -61, -1, 179, 100, 255, 203, -67, 112, 251, 98, -74, -573, -81, -85, -559, 130, -89, -100, 146, -370, 296, -107, -100, 548, 347, 145, 332, 172, -107, 846, -115, 184, -783, 3, 506, -825, -128
OFFSET
1,2
PROG
(PARI)
up_to = 32768;
v064413 = readvec("b064413_upto65539_terms_only.txt"); \\ From precomputed file.
A064413(n) = v064413[n];
\\ Then its inverse A064664 is prepared:
m064664 = Map();
for(n=1, 65539, mapput(m064664, A064413(n), n));
A064664(n) = mapget(m064664, n);
DirInverse(v) = { my(u=vector(#v)); u[1] = (1/v[1]); for(n=2, #v, u[n] = -sumdiv(n, d, if(d<n, v[n/d]*u[d], 0))); (u) }; \\ Compute the Dirichlet inverse of the sequence given in input vector v.
v323411 = DirInverse(vector(up_to, n, A064664(n)));
A323411(n) = v323411[n];
CROSSREFS
KEYWORD
sign
AUTHOR
Antti Karttunen, Jan 13 2019
STATUS
approved