A090478 - OEIS

A090478

a(1) = 1; for n>=1, a(n+1) is the least number such that the concatenation of a(n), n and a(n+1) is prime.

1, 3, 17, 3, 7, 1, 3, 3, 3, 7, 3, 9, 7, 17, 27, 17, 7, 7, 7, 3, 3, 7, 9, 9, 1, 9, 23, 9, 1, 1, 1, 9, 3, 1, 11, 1, 1, 3, 9, 1, 9, 3, 11, 7, 11, 47, 19, 1, 1, 3, 23, 11, 7, 7, 1, 3, 17, 3, 1, 7, 3, 3, 3, 1, 11, 7, 9, 7, 1, 3, 1, 17, 9, 3, 23, 3, 1, 7, 9, 1, 1, 1, 3, 3, 7, 3, 3, 7, 3, 17, 3, 1, 11, 3, 3, 11

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OFFSET

1,2

LINKS

Table of n, a(n) for n=1..96.

EXAMPLE

113, 3217, 1733 etc. are primes. 3217 is the prime obtained by placing 2 in the second gap.

CROSSREFS

Sequence in context: A285740 A174506 A109216 * A231785 A195421 A140446

Adjacent sequences: A090475 A090476 A090477 * A090479 A090480 A090481

KEYWORD

base,nonn

AUTHOR

Amarnath Murthy, Dec 02 2003

EXTENSIONS

More terms from David Wasserman, Nov 16 2005

STATUS

approved