A175405 Numbers m such that the resulting number h after iterations of {((((D_1^D_2)^D_3)^D_4)^...)^D_k, where D_k is the k-th digit D of the number r and k is the digit number of the number r in the decimal expansion of r (A055642)} needed to reach a one-digit number starting at r = n is equal to 1 (h = 1).

1, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 24, 26, 27, 28, 30, 33, 35, 36, 37, 38, 39, 40, 42, 43, 44, 45, 46, 47, 48, 49, 50

Offset

1,2

Links

Table of n, a(n) for n=1..33.

Example

For number a(14) = 26 we have iteration: {2^6 = 64}, {6^4 = 1296}, {((1^2)^9)^6 = 1}.

Crossrefs

Cf. A175398, A175399, A175400, A175401, A175402, A175403.

Sequence in context: A182363 A055982 A008717 * A225683 A326734 A256556

Adjacent sequences: A175402 A175403 A175404 * A175406 A175407 A175408

Keyword

nonn,base,more

Author

Jaroslav Krizek, May 01 2010

Status

approved