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 A065371 a(1) = 1, a(prime(i)) = prime(i) - i for i > 0 and a(u * v) = a(u) * a(v) for u, v > 0. 4
 1, 1, 1, 1, 2, 1, 3, 1, 1, 2, 6, 1, 7, 3, 2, 1, 10, 1, 11, 2, 3, 6, 14, 1, 4, 7, 1, 3, 19, 2, 20, 1, 6, 10, 6, 1, 25, 11, 7, 2, 28, 3, 29, 6, 2, 14, 32, 1, 9, 4, 10, 7, 37, 1, 12, 3, 11, 19, 42, 2, 43, 20, 3, 1, 14, 6, 48, 10, 14, 6, 51, 1, 52, 25, 4, 11, 18, 7, 57, 2, 1, 28, 60, 3, 20, 29 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,5 COMMENTS a(n) > 0 and a(n) < n for all n > 1. LINKS Reinhard Zumkeller, Table of n, a(n) for n = 1..10000 FORMULA a(1) = 1; for n > 1, a(n) = (A020639(n)-A055396(n)) * a(A032742(n)). - Antti Karttunen, Jan 12 2017 EXAMPLE a(210) = a(2*3*5*7) = a(2)*a(3)*a(5)*a(7) = (prime(1)-1)*(prime(2)-2)*(prime(3)-3)*(prime(4)-4) = (2-1)*(3-2)*(5-3)*(7-4) = 1*1*2*3 = 6. PROG (Haskell) a065371 1 = 1 a065371 n = product \$ map (a014689 . a049084) \$ a027746_row n -- Reinhard Zumkeller, Apr 09 2012 (Scheme, with memoization-macro definec) (definec (A065371 n) (cond ((= 1 n) 1) (else (* (- (A020639 n) (A055396 n)) (A065371 (A032742 n)))))) ;; Antti Karttunen, Jan 12 2017 CROSSREFS Cf. A000040, A014689, A020639, A027746, A032742, A049084, A055396, A065372, A065373, A065374. Sequence in context: A117811 A297381 A051793 * A300982 A186007 A212623 Adjacent sequences:  A065368 A065369 A065370 * A065372 A065373 A065374 KEYWORD mult,nonn AUTHOR Reinhard Zumkeller, Nov 01 2001 STATUS approved

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Last modified April 24 12:01 EDT 2019. Contains 322429 sequences. (Running on oeis4.)