[seqfan] Several errors in A128172
Hagen von Eitzen
math at von-eitzen.de
Tue Aug 4 21:23:49 CEST 2009
The values for n=10, 20, 30 seem to be wrong in A128172:
The pari code
V=[ 4700063497, 41459, 6821, 15853, 121129, 535, 36196439, 3827,
419064131135, 8153, 20395, 5805311, 93929, 3736136819, 1343851, 7099195,
319, 559, 9466429489, 5053, 1535, 280517, 148731221, 869, 2062919,
17473, 803, 39259, 35773546949 ]
for(i=1, #V, print1( lift( Mod(i+1,V[i])^V[i])-i-2," " ) )
outputs
0 0 0 0 0 0 0 0 247427183204 0 0 0 0 0 0 0 0 0 8539783357 0 0 0 0 0 0 0
0 0 6146401780
though it should be all zero.
Of course, a(10) = 15084115509707 can be copied from A127818(11), but
unfortunately A128160(21) and A128370(31) are still unknown.
I'm working on this and can hopefully submit all corrections at once in
a short while, but does anybody have an idea if the wrong numbers have
possibly some other significance? After all they occur exactly at the
multiples of 10 ...
Hagen
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