[seqfan] Re: Question regarding A069570

[Jeremy Gardiner]

I think also there are some terms missing from A069570 as it currently
stands, I have:

1,2,3,4,5,6,7,8,9,11,12,13,14,15,16,17,18,19,21,22,23,24,25,26,27,28,29,41,4
2,43,44,45,46,47,48,49,61,62,63,64,65,66,67,68,69,81,82,83,84,85,86,87,88,89
,111,112,113,114,115,116,117,118,119,121,122,123,124,125,126,127,128,129,141
,142,143,144,145,146,147,148,149,161,162,163,164,165,166,167,168,169,181,182
,183,184,185,186,187,188,189,311,312,313,314,315,316,317,318,319,321,322,323
,324,325,326,327,328,329,341,342,343,344,345,346,347,348,349,361,362,363,364
,365,366,367,368,369,381,382,383,384,385,386,387,388,389,611,612,613,614,615
,616,617,618,619,621,622,623,624,625,626,627,628,629,641,642,643,644,645,646
,647,648,649,661,662,663,664,665,666,667,668,669,681,682,683,684,685,686,687
,688,689,911,912,913,914,915,916,917,918,919,921,922,923,924,925,926,927,928
,929,941,942,943,944,945,946,947,948,949,961,962,963,964,965,966,967,968,969
,981,982,983,984,985,986,987,988,989

Terms 112,113,114,115,116,117,118,119, are missing in the original.

- I will submit a correction to the sequence.

By the way, I spotted a problem with this sequence (and also with A117230)
while searching for parity matches to A067251 (Numbers with no trailing
zeros in decimal representation) - a useful technique!

Jeremy
> 
> It appears that by "1st digit", the author means "least significant digit",
> so with 13, the first digit is 3 and the second is 1.
> 
> There is a typo in the sequence:  ...19, 18, 19,... should be
> ...17, 18, 19,...
> 
> The title should be reworded to something like
> "Numbers in which the n-th least significant digit is either a divisor
> or a non-zero multiple of n."
> 
> (added "least significant" and "non-zero")
> 
> Sequences A069571 through A069574 should include the same
> clarifications in their titles.
> 
> Andrew
>