

A053008


Primes from products of split evendigit primes.


3



3, 7, 3, 7, 103, 109, 103, 409, 601, 109, 709, 907, 523, 139, 193, 853, 379, 397, 739, 937, 499, 223, 499, 1621, 2161, 6121, 6211, 4261, 4621, 6421, 2017, 2551, 5521, 139, 193, 769, 967, 997, 109, 3001, 1039, 1093, 3019, 3109, 9013, 9103, 4111, 1153, 1531
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OFFSET

1,1


REFERENCES

C. A. Pickover, chapter 30 of Keys to Infinity. NY: Wiley, 1995. Pages 227231.


LINKS

Table of n, a(n) for n=1..49.
Sean A. Irvine, Java program (github)


FORMULA

Take evendigit primes, split digits into two halves, multiply the halves and form primes by rearranging digits. If split in right half results in a leading zero, that prime is skipped.
If more than one prime can be formed from the digits of the product, then each appears in numerical order. Consequently this sequence is not in onetoone correspondence with the terms of A053009 and A053010.  Sean A. Irvine, Dec 02 2021


EXAMPLE

103 is a term because from the prime 1013 we get 10 and 13 after the split; 10*13=130 and the digits 1 3 0 can be arranged to form 103, prime.


CROSSREFS

Cf. A053009, A053010.
Sequence in context: A151573 A113832 A115631 * A053010 A118452 A286090
Adjacent sequences: A053005 A053006 A053007 * A053009 A053010 A053011


KEYWORD

easy,nonn,base


AUTHOR

Enoch Haga, Feb 21 2000


EXTENSIONS

Missing terms inserted by Sean A. Irvine, Dec 02 2021


STATUS

approved



