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A328623
Inverse permutation to A328622.
8
0, 1, 4, 5, 2, 3, 18, 19, 22, 23, 20, 21, 6, 7, 10, 11, 8, 9, 24, 25, 28, 29, 26, 27, 12, 13, 16, 17, 14, 15, 120, 121, 124, 125, 122, 123, 138, 139, 142, 143, 140, 141, 126, 127, 130, 131, 128, 129, 144, 145, 148, 149, 146, 147, 132, 133, 136, 137, 134, 135, 30, 31, 34, 35, 32, 33, 48, 49, 52, 53, 50, 51, 36, 37, 40, 41, 38, 39, 54, 55, 58, 59, 56, 57, 42
OFFSET
0,3
FORMULA
a(n) = A276085(A328619(A276086(n))).
PROG
(PARI)
A002110(n) = prod(i=1, n, prime(i));
A276085(n) = { my(f = factor(n)); sum(k=1, #f~, f[k, 2]*A002110(primepi(f[k, 1])-1)); };
A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
A328619(n) = { my(f = factor(n), m, q); for(k=1, #f~, q = (f[k, 2]\f[k, 1]); m = (f[k, 2]%f[k, 1]); if(m&&(f[k, 1]!=2), f[k, 2] = q*f[k, 1] + lift(Mod(m, f[k, 1])/2))); factorback(f); };
CROSSREFS
Cf. A328622 (inverse), and also A289234.
Sequence in context: A335615 A328622 A338248 * A225901 A354469 A030322
KEYWORD
nonn,base
AUTHOR
Antti Karttunen, Oct 23 2019
STATUS
approved