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 A144122 (1, 2, 3, 2^2, 5, 2*3, 7, 2^3, 3^2, 2*5, 11, 2^2*3, 13, ...) becomes (0, 1, 4, 6^8, 9, 10*12, 14, 15^16, 18^20, 21*22, 24, 25^26*27, 28, ...). 1
 0, 1, 4, 1679616, 9, 120, 14, 6568408355712890625, 12748236216396078174437376, 462, 24, 59952043329758453182876110076904296875, 28, 960, 1122, 38587762477395204358312525169472792185842990875244140625, 38 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 LINKS EXAMPLE 6^8 = 1679616 = a(4), 9 = a(5), 10*12 = 120 = a(6), etc. MAPLE A141468 := proc(n) if n <=2 then n-1; else for a from procname(n-1)+1 do if not isprime(a) then return a; end if; end do: end if; end proc: A144122 := proc(nmax) local a, ifs, n, p, c ; printf("0, 1, ") ; c := 3 ; for n from 3 to nmax do ifs := ifactors(n)[2] ; a := 1; for p in ifs do if op(2, p) > 1 then a := a*A141468(c)^A141468(c+1) ; c := c+2 ; else a := a*A141468(c) ; c := c+1 ; fi; od: printf("%d, ", a) ; od: return ; end: A144122(20) ; # R. J. Mathar, Apr 28 2010 CROSSREFS Cf. A141468, A141186, A143677. Sequence in context: A090096 A218484 A046362 * A058424 A204041 A065248 Adjacent sequences:  A144119 A144120 A144121 * A144123 A144124 A144125 KEYWORD nonn AUTHOR Juri-Stepan Gerasimov, Nov 17 2008 EXTENSIONS More terms from R. J. Mathar, Apr 28 2010 STATUS approved

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Last modified January 28 22:57 EST 2022. Contains 350669 sequences. (Running on oeis4.)