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A068890
a(1) = 1; a(n) = smallest nontrivial n-th power with property that digits alternate in parity.
1
1, 4, 8, 16, 32, 729, 2187, 256
OFFSET
1,2
COMMENTS
Conjecture: the sequence is finite.
For all n>=1, (n^10 mod 1000) is one of {0, 1, 24, 49, 176, 201, 224, 249, 376, 401, 424, 449, 576, 601, 624, 625, 649, 776, 801, 824, 849, 976}. None of these have digits of alternating parity, thus a(10) does not exist. - Benjamin Chaffin, Nov 24 2021
CROSSREFS
Sequence in context: A049932 A272712 A020161 * A073856 A019458 A264166
KEYWORD
nonn,base,fini
AUTHOR
Amarnath Murthy, Mar 20 2002
STATUS
approved