login
A307267
Row 24 of array in A059897.
3
24, 12, 8, 6, 120, 4, 168, 3, 216, 60, 264, 2, 312, 84, 40, 384, 408, 108, 456, 30, 56, 132, 552, 1, 600, 156, 72, 42, 696, 20, 744, 192, 88, 204, 840, 54, 888, 228, 104, 15, 984, 28, 1032, 66, 1080, 276, 1128, 128, 1176, 300, 136, 78, 1272, 36, 1320, 21, 152, 348, 1416, 10
OFFSET
1,1
COMMENTS
Also column 24 of A059897.
A self-inverse permutation of the positive integers with no fixed points; a composition of A073675, A120229 and A120230.
The permutation swaps pairs of integers whose ratio is 1:24, 1:6, 3:8 or 2:3, these ratios corresponding to the factorizations 1*24 = 2*12 = 3*8 = 4*6 = 24. Row 24 is the first row of A059897 to exhibit more than 2 such ratios.
FORMULA
a(n) = A059897(24,n) = A059897(n,24).
a(n) = A073675(A120229(A120230(n))) = A073675(n) * A120229(n) * A120230(n) / n^2.
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, 24); \\ Michel Marcus, Apr 23 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
Peter Munn, Apr 01 2019
STATUS
approved