A242912 Finite sequence where each term follows n*10^n + p, where p is an n-digit prime and 1 <= n <= 9.

12, 13, 15, 17, 211, 213, 217, 219, 223, 229, 231, 237, 241, 243, 247, 253, 259, 261, 267, 271, 273, 279, 283, 289, 297, 3101, 3103, 3107, 3109, 3113, 3127, 3131, 3137, 3139, 3149, 3151, 3157, 3163, 3167, 3173, 3179, 3181, 3191, 3193, 3197, 3199, 3211, 3223

Offset

1,1

Comments

The sequence is finite because only the first digit is considered in defining the entire number. This first digit can vary only between 1 and 9. Hence, the largest possible number must be 9000000000 + p, where p is a 9-digit prime number. The largest prime I have found that fits this category is 999999937, giving the term, 9999999937.

Links

Table of n, a(n) for n=1..48.

Example

For n = 2, 2*10^2 + 19 = 219. 19 is a 2-digit prime.
Note that for each n, several a(i) are generated, and the first of these is related to the 1st prime with n-digits. For n=1, the first term we get is related to the 1st prime with 1 digit, and there 4 of them. For n=2, the first term we get is related to the 1st prime with 2 digits and there 21 of them, etc.

Prog

(PARI) lista() = {for (n=1, 9, forprime(p=10^(n-1), 10^n-1, print1(n*10^n+p, ", "); ); ); } \\ Michel Marcus, May 27 2014

Crossrefs

Sequence in context: A074164 A076085 A039790 * A102496 A267615 A323032

Adjacent sequences: A242909 A242910 A242911 * A242913 A242914 A242915

Keyword

nonn,base,fini

Author

Philip Mizzi, May 26 2014

Status

approved