A069615 a(1) = 3; a(2n) = smallest prime starting (in 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.

3, 31, 131, 1319, 21319, 213193, 12213193, 122131939, 1122131939, 112213193957, 27112213193957, 271122131939573, 3271122131939573, 327112213193957339, 2327112213193957339, 232711221319395733969, 13232711221319395733969

Offset: 1

Author

Amarnath Murthy, Mar 27 2002

Keywords

• nonn
• base
• more

Examples

			a(4) = 1319 starting with a(3) = 131 and a(5) = 21319 ending in a(4) = 1319.
		

Crossrefs

Cf. A053582, A069605, A069606, A069607, A069608, A069609, A069610, A069611, A069613, A069614.

Extensions

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