A194766 Numbers which can be written using their digits in order and only multiplication and squaring operators.

128, 175, 384, 672, 735, 1296, 6144, 18432, 23328, 34992, 82944, 442368, 1492992, 2333772, 2612736, 3981312, 4128768, 9289728, 12192768, 13226976, 13395375, 13436928, 21233664, 22127616, 27869184, 49787136, 161243136

Offset

1,1

Links

Table of n, a(n) for n=1..27.

Erich Friedman, Problem of the month August 2003

Example

128 = 1*2^2*8. 175=1*7*5^2. 384=3*8*4^2. 672=6*7*(2^2)^2.
735 = 7^2*3*5. 1296 = 1*2^2*9*6^2. 6144=6*4*(4^2)^2.
21233664 = ((2^2)^2)^2*1*(2^2)^2*3*3*6*6*4^2.

Crossrefs

Sequence in context: A130445 A114565 A243812 * A257211 A109651 A114408

Adjacent sequences: A194763 A194764 A194765 * A194767 A194768 A194769

Keyword

nonn,base

Author

Kausthub Gudipati, Sep 02 2011

Extensions

Example corrected by Harvey P. Dale, Aug 20 2012

Status

approved