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A053008 Primes from products of split even-digit primes. 2
3, 7, 3, 7, 103, 109, 103, 409, 601, 109, 709, 907, 523, 139, 193, 853, 379, 397, 739, 937, 499, 223, 499, 1621, 6121, 6211, 4261, 6421, 2017, 2551, 5521, 139, 769, 967, 997, 109, 4111, 1153, 1531, 3511, 859, 139, 193, 1873, 3187, 8317, 1051, 5011, 1483 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

REFERENCES

C. A. Pickover, chapter 30 of Keys to Infinity. NY: Wiley, 1995. Pages 227-231.

LINKS

Table of n, a(n) for n=0..48.

FORMULA

Take even-digit 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.]

EXAMPLE

a(5)=103 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

STATUS

approved

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Last modified October 22 08:00 EDT 2019. Contains 328315 sequences. (Running on oeis4.)