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 A127432 a(0)=1. a(n) = number of earlier terms a(k), 0<=k<=n-1, such that (k+n) is divisible by a(k). 3
 1, 1, 2, 2, 3, 4, 3, 4, 4, 5, 3, 7, 5, 5, 5, 5, 6, 8, 5, 4, 8, 8, 5, 9, 6, 6, 8, 8, 7, 9, 7, 9, 10, 9, 4, 10, 9, 8, 12, 7, 7, 11, 9, 9, 9, 12, 9, 13, 11, 7, 9, 12, 10, 12, 9, 9, 12, 12, 13, 13, 8, 10, 13, 14, 6, 12, 12, 12, 17, 10, 11, 14, 12, 12, 9, 14, 11, 16, 13, 12, 14, 13, 9, 16, 16, 12, 13 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS Rémy Sigrist, Table of n, a(n) for n = 0..10000 Rémy Sigrist, C program for A127432 EXAMPLE (0+9) is a multiple of a(0)=1; (1+9) is a multiple of a(1)=1; (3+9) is a multiple of a(3)=2; (6+9) is a multiple of a(6)=3 and (7+9) is a multiple of a(7)=4. These five cases are the only cases where (k+n) is divisible by a(k), for 0<=k<=8. So a(9) = 5. MATHEMATICA f[l_List] := Block[{n = Length[l]}, Append[l, Count[Table[Mod[k + n - 1, l[[k]]], {k, n}], 0]]]; Nest[f, {1}, 87] (* Ray Chandler, Jan 22 2007 *) PROG (C) See Links section. CROSSREFS Cf. A127431, A127434. Sequence in context: A056796 A061295 A081742 * A199408 A285325 A135529 Adjacent sequences: A127429 A127430 A127431 * A127433 A127434 A127435 KEYWORD nonn,look AUTHOR Leroy Quet, Jan 14 2007 EXTENSIONS Extended by Ray Chandler, Jan 22 2007 STATUS approved

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Last modified December 7 04:56 EST 2023. Contains 367629 sequences. (Running on oeis4.)