The smallest prime formed from the concatenation of n
consecutive n-digit composite numbers in the pattern {a, b,
c, d, e, f, g, f, e, d, c, b, a}, i.e., {1000019, 1000020,
1000021, 1000022, 1000023, 1000024, 1000025, 1000024,
1000023, 1000022, 1000021, 1000020, 1000019}, (case n=7). [Bajpai]