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 A287707 a(1) = 1, a(2) = a(4) = a(5) = 2, a(3) = 3, a(n) = a(a(n-1)) + a(a(n-a(n-1)) + a(n-a(n-2))) for n > 5. 3
 1, 2, 3, 2, 2, 4, 4, 4, 4, 6, 8, 8, 6, 8, 8, 8, 8, 12, 16, 12, 12, 16, 16, 12, 14, 16, 16, 16, 16, 16, 16, 16, 16, 20, 24, 20, 20, 24, 24, 20, 24, 28, 28, 24, 24, 28, 32, 28, 28, 32, 32, 28, 32, 32, 32, 28, 32, 32, 32, 32, 32, 32, 32, 32, 32, 36, 40, 36, 36, 40, 40, 36, 40, 44, 44, 40, 40, 48, 48, 44, 44, 52, 48 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Altug Alkan, Table of n, a(n) for n = 1..10000 Altug Alkan, Plot of a(n)-n/2 Indranil Ghosh, Python program to compute the sequence MAPLE N:= 2^10: # to get a(1) to a(N) C[1]:= 1: C[2]:= 2: C[3]:= 3: C[4]:= 2: C[5]:= 2: for n from 6 to N do C[n]:= C[C[n-1]] + C[C[n-C[n-1]] + C[n-C[n-2]]]; od: S:=seq(C[n], n=1..N); PROG (Scheme) ;; An implementation of memoization-macro definec can be found for example in: http://oeis.org/wiki/Memoization (definec (A287707 n) (cond ((or (= 1 n) (= 3 n)) n) ((<= n 5) 2) (else (+ (A287707 (A287707 (- n 1))) (A287707 (+ (A287707 (- n (A287707 (- n 1)))) (A287707 (- n (A287707 (- n 2)))))))))) ;; Antti Karttunen, May 31 2017 CROSSREFS Cf. A004001, A005185, A287654. Sequence in context: A098534 A317638 A002307 * A029247 A194020 A053269 Adjacent sequences:  A287704 A287705 A287706 * A287708 A287709 A287710 KEYWORD nonn AUTHOR Altug Alkan, May 30 2017 STATUS approved

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Last modified December 12 07:31 EST 2019. Contains 329948 sequences. (Running on oeis4.)