|
|
A292265
|
|
A multiplicative encoding (compressed) for the exponents of 2 obtained when using Shevelev's algorithm for computing A002326.
|
|
7
|
|
|
2, 3, 12, 6, 20, 180, 720, 5, 80, 25920, 20, 360, 43200, 25920, 6220800, 10, 240, 540, 671846400, 540, 57600, 2160, 540, 194400, 155520, 45, 5804752896000, 77760, 14400, 87071293440000, 348285173760000, 15, 960, 12538266255360000, 311040, 139968000, 120, 77760, 18662400, 1679616000, 23219011584000, 108330620446310400000, 60, 4665600, 360, 540, 180
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,1
|
|
COMMENTS
|
a(n) = A019565(v(1)) * A019565(v(2)) * ... * A019565(v(k)), where v(1) .. v(k) are 2-adic valuations (not all necessarily distinct) of the iterated values obtained when running Shevelev's algorithm for computing A002623. (See A179680 and A292239.)
|
|
LINKS
|
|
|
FORMULA
|
|
|
PROG
|
(PARI)
A000265(n) = (n >> valuation(n, 2));
A019565(n) = {my(j, v); factorback(Mat(vector(if(n, #n=vecextract(binary(n), "-1..1")), j, [prime(j), n[j]])~))}; \\ This function from M. F. Hasler
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|