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A330193
a(n) is the length of the decimal expansion of A330192(n)^A330192(n).
2
1, 1, 1, 2, 3, 4, 5, 6, 8, 9, 11, 55, 77, 88, 444, 555, 666, 888, 999, 1111, 4444, 5555, 6666, 9999, 11111, 55555, 99999, 333333, 444444, 666666, 888888, 999999, 1111111, 7777777, 33333333, 88888888, 333333333, 999999999, 5555555555, 222222222222, 44444444444444
OFFSET
1,4
LINKS
Cristian Cobeli, DOI^2, arXiv:1911.09003 [math.HO], 2019. See Table 2 p. 8.
Cristian Cobeli, DOI^2, Romanian Journal Of Pure And Applied Mathematics, Tome LXVI, No. 3-4, 2021.
FORMULA
a(n) = A066022(A330192(n)).
a(n) = A055642(A330192(n)^A330192(n)).
MATHEMATICA
Flatten@ Reap[Sow[1]; Do[v = d (10^nd - 1)/9; s = Solve[v-1 <= x Log10[x] < v, x, Integers]; If[s != {}, Sow[v /. s]], {nd, 15}, {d, 9}]][[2, 1]] (* Giovanni Resta, Dec 05 2019 *)
CROSSREFS
Cf. A010785 (repdigits), A000312 (n^n), A055642, A066022, A330192.
Sequence in context: A226189 A235592 A100054 * A372667 A101271 A093110
KEYWORD
nonn,base
AUTHOR
Michel Marcus, Dec 05 2019
EXTENSIONS
a(28)-a(41) from Giovanni Resta, Dec 05 2019
STATUS
approved