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A033681 a(1) = 3; a(n) is smallest number >= a(n-1) such that the juxtaposition a(1)a(2)...a(n) is a prime. 12
3, 7, 9, 51, 51, 51, 97, 131, 157, 159, 243, 309, 327, 363, 383, 411, 487, 639, 873, 983, 1231, 1257, 1337, 1549, 1589, 2101, 2159, 2317, 2871, 2907, 4053, 4097, 4597, 4703, 5559, 5799, 6337, 6527, 6561, 6939, 7147, 7167, 7839, 8403, 8873, 9237, 9541, 9771 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

MATHEMATICA

a[1] = 3; a[n_] := a[n] = Block[{k = a[n - 1], c = IntegerDigits @ Table[ a[i], {i, n - 1}]}, While[ !PrimeQ[ FromDigits @ Flatten @ Append[c, IntegerDigits[k]]], k += 2]; k]; Table[ a[n], {n, 48}] (* Robert G. Wilson v *)

CROSSREFS

Cf. A069605, A074339, A033680, A033679, A046254, A046255, A046256, A046257, A046258, A046259, A111524.

Sequence in context: A013624 A053366 A128052 * A074339 A115164 A003033

Adjacent sequences:  A033678 A033679 A033680 * A033682 A033683 A033684

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

EXTENSIONS

More terms from Patrick De Geest, May 15, 1998.

More terms from Robert G. Wilson v, Aug 05 2005

STATUS

approved

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Last modified May 20 11:01 EDT 2013. Contains 225459 sequences.