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 A267107 "Manta moth permutation": a(1) = 1, a(A080147(n)) = A080148(a(n)), a(A080148(n)) = A080147(a(n)). 8
 1, 3, 2, 7, 6, 5, 4, 16, 13, 14, 12, 11, 9, 10, 35, 8, 29, 31, 30, 26, 23, 25, 21, 27, 22, 20, 24, 74, 17, 19, 18, 62, 67, 66, 15, 65, 54, 57, 51, 58, 55, 56, 45, 48, 43, 59, 50, 44, 53, 47, 39, 152, 49, 37, 41, 42, 38, 40, 46, 144, 130, 32, 139, 137, 36, 34, 33, 118, 136, 129, 128, 113, 121, 28, 108, 122, 125 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS This is self-inverse permutation of natural numbers. LINKS Antti Karttunen, Table of n, a(n) for n = 1..10001 FORMULA a(1) = 1; and for n > 1, if prime(n) modulo 4 = 1, a(n) = A080148(a(A267097(n))), otherwise a(n) = A080147(a(A267098(n))). PROG (PARI) allocatemem(2^30); default(primelimit, 4294965247); uplim = 2^20; uplim2 = 366824; \\ Very ad hoc. v080147 = vector(uplim); v080148 = vector(uplim); v267097 = vector(uplim); v267107 = vector(uplim); v267097[1] = 0; c = 0; v47i = 0; v48i = 0; for(n=2, uplim, if((1 == (prime(n)%4)), c++; v47i++; v080147[v47i] = n, v48i++; v080148[v48i] = n); v267097[n] = c; if(!(n%32768), print1(" n=", n))); A080147(n) = v080147[n]; A080148(n) = v080148[n]; A267097(n) = v267097[n]; A267098(n) = (n - A267097(n))-1; A267107(n) = v267107[n]; v267107[1] = 1; for(n=2, uplim2, if((1 == (prime(n) % 4)), v267107[n] = A080148(A267107(A267097(n))), v267107[n] = A080147(A267107(A267098(n))));  if(!(n%32768), print1(" n=", n))); for(n=1, uplim2, write("b267107.txt", n, " ", A267107(n))); (Scheme, with memoization-macro definec) (definec (A267107 n) (cond ((<= n 1) n) ((= 1 (modulo (A000040 n) 4)) (A080148 (A267107 (A267097 n)))) (else (A080147 (A267107 (A267098 n)))))) CROSSREFS Cf. A000040, A002144, A002145, A080147, A080148, A267097, A267098. Cf. A268393 (record positions), A268394 (record values). Cf. also A267100, A267105, A267106. Sequence in context: A054429 A269398 A269397 * A126316 A101224 A229120 Adjacent sequences:  A267104 A267105 A267106 * A267108 A267109 A267110 KEYWORD nonn,look AUTHOR Antti Karttunen, Feb 01 2016 STATUS approved

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Last modified August 14 17:44 EDT 2018. Contains 313751 sequences. (Running on oeis4.)