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A104224 Sum of the smallest and the largest n-digit primes. 1
9, 108, 1098, 10982, 109998, 1099986, 10999994, 110000008, 1099999944, 10999999974, 109999999996, 1099999999992, 11000000000010, 110000000000010, 1100000000000020, 10999999999999974, 110000000000000058 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

LINKS

Chris Caldwell The First 10,000 Primes.

EXAMPLE

The first term is 9 since it is the sum of 2 and 7, the smallest and largest of 1-digit primes.

PROG

(Sage) def A104224(n): return next_prime(10**(n-1))+previous_prime(10**n) # [D. S. McNeil, Feb 3 2011]

CROSSREFS

Sequence in context: A122569 A039619 A080505 * A099676 A166907 A051606

Adjacent sequences:  A104221 A104222 A104223 * A104225 A104226 A104227

KEYWORD

nonn,base

AUTHOR

Parthasarathy Nambi (PachaNambi(AT)yahoo.com), Apr 01 2005

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Last modified February 16 12:15 EST 2012. Contains 205909 sequences.