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A069619
a(1) = 7; a(2n) = smallest prime that is a right concatenation of a(2n-1) and a number with no insignificant zeros and a(2n+1) = smallest prime ending in ( the least significant digits) a(2n-1). Alternate left and right concatenation yielding primes.
2
7, 71, 271, 2711, 52711, 5271121, 135271121, 1352711219, 271352711219, 27135271121911, 1227135271121911, 122713527112191161, 20122713527112191161, 20122713527112191161109, 2720122713527112191161109
OFFSET
1,1
EXAMPLE
a(4) = 2711 staring with a(3) =271 and a(5) = 52711 in a(4) = 2711.
KEYWORD
nonn,base
AUTHOR
Amarnath Murthy, Mar 27 2002
EXTENSIONS
More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Mar 30 2003
STATUS
approved