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A082887
a(n)=gcd[mod[n!,2^n],mod[(n+1)!,2^(n+1)]].
0
1, 2, 2, 8, 8, 16, 16, 128, 384, 256, 256, 3072, 1024, 2048, 2048, 32768, 98304, 65536, 65536, 262144, 262144, 524288, 524288, 4194304, 4194304, 8388608, 8388608, 33554432, 33554432, 67108864, 67108864, 2147483648, 6442450944, 4294967296
OFFSET
0,2
EXAMPLE
n=12:mod[12!,4096,]=mod[13!,8192]=3072, gcd[3072,3072]=3072=a(12).
MATHEMATICA
Table[GCD[Mod[w!, 2^w], Mod[(w+1)!, 2^(w+1)]], {w, 1, 50}]
CROSSREFS
Sequence in context: A072576 A271342 A060818 * A137583 A099328 A073090
KEYWORD
easy,nonn
AUTHOR
Labos Elemer, Apr 22 2003
STATUS
approved