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 A347097 a(1) = 2; and for n > 1, a(n) = A341512(n) + A347096(n). 4
 2, 0, 0, 1, 0, 4, 0, 21, 4, 4, 0, 110, 0, 8, 8, 259, 0, 224, 0, 154, 16, 4, 0, 1548, 4, 8, 176, 316, 0, 592, 0, 2445, 8, 4, 16, 4312, 0, 8, 16, 2450, 0, 1216, 0, 382, 640, 12, 0, 15532, 16, 408, 8, 616, 0, 6708, 8, 5064, 16, 4, 0, 12272, 0, 12, 1312, 19543, 16, 1504, 0, 754, 24, 1568, 0, 50561, 0, 8, 832, 1060, 16 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Sum of {the pointwise sum of A341512 and A063524 (1, 0, 0, 0, ...)} and its Dirichlet inverse. The first negative term is a(5760) = -1223227750. LINKS FORMULA a(1) = 2, and for n>1, a(n) = -Sum_{d|n, 1= 1, a(A001248(n)) = A001223(n)^2. PROG (PARI) up_to = 16384; A003961(n) = { my(f=factor(n)); for (i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); }; \\ From A003961 A341512(n) = { my(u=A003961(n)); ((sigma(n)*u) - (n*sigma(u))); }; DirInverseCorrect(v) = { my(u=vector(#v)); u[1] = (1/v[1]); for(n=2, #v, u[n] = (-u[1]*sumdiv(n, d, if(d

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Last modified January 27 21:45 EST 2022. Contains 350654 sequences. (Running on oeis4.)