A069614 a(1) = 2; a(2n) = smallest prime starting (the most significant digits) with a(2n-1) (i.e., as a right concatenation of a(2n-1) and a number with no insignificant zeros); a(2n+1) = smallest prime ending in (the least significant digits) a(2n-1). Alternate left and right concatenation yielding primes.

2, 23, 223, 2237, 32237, 3223729, 63223729, 632237297, 2632237297, 263223729721, 12263223729721, 1226322372972173, 171226322372972173, 17122632237297217381, 2117122632237297217381, 21171226322372972173813

Offset: 1

Author

Amarnath Murthy, Mar 27 2002

Keywords

• nonn
• base

Examples

			a(4) = 2111 starting with a(3) = 211 and a(5) = 22111 ending in a(4) = 2111.
		

Crossrefs

Cf. A053582, A069605, A069606, A069607, A069608, A069609, A069610, A069611, A069613.

Extensions

More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Mar 30 2003