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A307266
Row 8 of array in A059897.
3
8, 4, 24, 2, 40, 12, 56, 1, 72, 20, 88, 6, 104, 28, 120, 128, 136, 36, 152, 10, 168, 44, 184, 3, 200, 52, 216, 14, 232, 60, 248, 64, 264, 68, 280, 18, 296, 76, 312, 5, 328, 84, 344, 22, 360, 92, 376, 384, 392, 100, 408, 26, 424, 108, 440, 7, 456, 116, 472, 30, 488, 124, 504, 32
OFFSET
1,1
COMMENTS
Also column 8 of A059897.
A self-inverse permutation of the positive integers with no fixed points; A073675 composed with A120230.
The permutation swaps pairs of integers whose ratio is 1:8 or 1:2, these ratios corresponding to the factorizations 1*8 = 2*4 = 8.
FORMULA
a(n) = A059897(8,n) = A059897(n,8).
a(n) = A073675(A120230(n)) = A120230(A073675(n)) = A073675(n) * A120230(n) / n.
PROG
(PARI) T(n, k) = {if (n==1, return (k)); if (k==1, return (n)); my(fn=factor(n), fk=factor(k)); vp = setunion(fn[, 1]~, fk[, 1]~); prod(i=1, #vp, vp[i]^(bitxor(valuation(n, vp[i]), valuation(k, vp[i])))); }
a(n) = T(n, 8); \\ Michel Marcus, Apr 23 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
Peter Munn, Apr 01 2019
STATUS
approved