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 A330225 Position of first appearance of n in A290103 = LCM of prime indices. 2
 1, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 35, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Appears to be the prime numbers (A000040) with 2 replaced by 1 and 37 replaced by 35. A prime index of n is a number m such that prime(m) divides n. The multiset of prime indices of n is row n of A112798. LINKS MATHEMATICA primeMS[n_]:=If[n==1, {}, Flatten[Cases[FactorInteger[n], {p_, k_}:>Table[PrimePi[p], {k}]]]]; q=Table[If[n==1, 1, LCM@@primeMS[n]], {n, 100}]; Table[Position[q, i][[1, 1]], {i, First[Split[Union[q], #1+1==#2&]]}] CROSSREFS The version for product instead of lcm is A318871 The version for standard compositions is A333225. The version for binary indices is A333492. Let q(k) be the prime indices of k: - The product of q(k) is A003963(k). - The sum of q(k) is A056239(k). - The terms of q(k) are row k of A112798. - The GCD of q(k) is A289508(k). - The LCM of q(k) is A290103(k). - The LCM of q(k) + 1 is A328219(k). Cf. A000837, A074761, A074971, A076078, A285572, A289509, A290104, A319333, A324837, A328451, A331579, A333226. Sequence in context: A210494 A338483 A318871 * A275938 A093893 A056912 Adjacent sequences:  A330222 A330223 A330224 * A330226 A330227 A330228 KEYWORD nonn AUTHOR Gus Wiseman, Mar 26 2020 STATUS approved

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Last modified April 10 15:07 EDT 2021. Contains 342845 sequences. (Running on oeis4.)