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 A280692 a(n) = A003961(n) - A250469(n). 4
 0, 0, 0, 0, 0, 0, 0, 6, 0, -6, 0, 12, 0, -6, 0, 36, 0, 24, 0, 6, 0, -24, 0, 66, 0, -24, 60, 18, 0, 18, 0, 150, -20, -42, 0, 120, 0, -42, -10, 72, 0, 42, 0, -12, 60, -48, 0, 264, 0, 0, -30, 0, 0, 216, 0, 132, -30, -78, 0, 138, 0, -72, 120, 540, 0, 0, 0, -30, -30, 24, 0, 462, 0, -96, 60, -18, 0, 24, 0, 330, 420, -114, 0, 246 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,8 LINKS Antti Karttunen, Table of n, a(n) for n = 1..10067 FORMULA a(n) = A003961(n) - A250469(n). MATHEMATICA f[n_] := f[n] = Which[n == 1, 1, PrimeQ@ n, NextPrime@ n, True, Times @@ Replace[FactorInteger[n], {p_, e_} :> f[p]^e, 1]]; g[n_] := If[n == 1, 0, PrimePi@ FactorInteger[n][[1, 1]]]; Function[s, MapIndexed[ Function[{m, n}, f@ n - Lookup[s, g[n] + 1][[m]] + Boole[n == 1]][#1, First@ #2] &, #] &@ Map[Position[Lookup[s, g@ #], #][[1, 1]] &, Range@ 120]]@ PositionIndex@ Array[g, 10^4]] (* Michael De Vlieger, Mar 09 2017, Version 10 *) PROG (Scheme) (define (A280692 n) (- (A003961 n) (A250469 n))) CROSSREFS Cf. A003961, A250469, A249820, A280492, A280497, A280498, A280702. Cf. A280693 (gives the positions of zeros). Cf. also arrays A083221 and A246278. Sequence in context: A198368 A064373 A195290 * A161419 A136526 A097715 Adjacent sequences:  A280689 A280690 A280691 * A280693 A280694 A280695 KEYWORD sign AUTHOR Antti Karttunen, Mar 08 2017 STATUS approved

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Last modified August 20 10:05 EDT 2019. Contains 326149 sequences. (Running on oeis4.)