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A048643 Differences between partial products of Gray code (A048642) and factorials (A000142). 1
0, 0, 1, 0, 12, 132, 540, 0, 20160, 423360, 8164800, 125193600, 1172102400, 11935123200, 76281004800, 0, 10461394944000, 428917192704000, 14781951055872000, 429147343392768000, 14090871305871360000, 461146030563778560000, 13730871481551544320000, 390084405122331279360000 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,5
COMMENTS
a((2^n)-1) = 0 for all n.
LINKS
FORMULA
a(0) = 0, a(n) = product(XORnos(j, floor(j/2)), j=1..n) - n!.
a(n) = A048642(n) - A000142(n).
PROG
(PARI) a(n) = prod(i=1, n, bitxor(i, i>>1)) - n!; \\ Michel Marcus, Oct 02 2015
CROSSREFS
Sequence in context: A260018 A078218 A305261 * A111085 A002721 A340508
KEYWORD
easy,nonn
AUTHOR
Antti Karttunen, Jul 14 1999
EXTENSIONS
More terms from Michel Marcus, Oct 02 2015
STATUS
approved

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Last modified March 18 22:34 EDT 2024. Contains 370951 sequences. (Running on oeis4.)