A226032 Numbers of the form xyz, where x and z have the same number of digits and x*z = y.

100, 111, 122, 133, 144, 155, 166, 177, 188, 199, 200, 221, 242, 263, 284, 300, 331, 362, 393, 400, 441, 482, 500, 551, 600, 661, 700, 771, 800, 881, 900, 991, 2105, 2126, 2147, 2168, 2189, 3124, 3155, 3186, 3217, 3248, 3279, 4123, 4164, 4205, 4246, 4287, 4328

Offset

1,1

Comments

The same digit may not be used twice as both an "outer" and "inner" digit. For example, 11211 is not in the sequence, but 1112111 is.

Leading zeros are not allowed.

Links

Christian N. K. Anderson, Table of n, a(n) for n = 1..10000

Example

482 is in the sequence because 4*2 = 8.
4205 is in the sequence because 4*5 = 20.
100 is in the sequence because 1*0 = 0. However, 1200 is not because even though 12*0 = 0, 12 and 0 do not have the same number of digits. Likewise, 12|0|00 and 12|00|00 are not in the sequence because leading zeros are not allowed.

Prog

(R)
y=c(); for(i in 1:9) for(j in 0:9) y=c(y, as.numeric(paste(i, i*j, j, sep=""))); sort(y)

Crossrefs

Sequence in context: A066511 A281193 A285776 * A373066 A286699 A171222

Adjacent sequences: A226029 A226030 A226031 * A226033 A226034 A226035

Keyword

nonn,base

Author

Alan Wing-lun, Christian N. K. Anderson, Kevin L. Schwartz, May 23 2013

Status

approved