A302801 a(n) is the number whose digits result from the concatenation of the digits of n and the digits of the product of the digits of n.
0, 11, 22, 33, 44, 55, 66, 77, 88, 99, 100, 111, 122, 133, 144, 155, 166, 177, 188, 199, 200, 212, 224, 236, 248, 2510, 2612, 2714, 2816, 2918, 300, 313, 326, 339, 3412, 3515, 3618, 3721, 3824, 3927, 400, 414, 428, 4312, 4416, 4520, 4624, 4728, 4832, 4936, 500, 515
Offset: 0
Examples
For n=10, the digits of n are 1 and 0, their product is 0, and the concatenation gives 1 0 0.
Links
Programs
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Mathematica
Table[FromDigits[Join[IntegerDigits[n],IntegerDigits[Product[Part[IntegerDigits[n],k],{k,Length[IntegerDigits[n]]}]]]],{n,0,51}] (* Stefano Spezia, Aug 13 2023 *) -
PARI
mydigits(n) = if (n, digits(n), [0]); a(n) = my(d = mydigits(n)); fromdigits(concat(d, mydigits(prod(k=1, #d, d[k]))));