A114321 Difference between first odd semiprime > 11^n and 11^n.

8, 4, 2, 2, 6, 14, 4, 6, 6, 6, 4, 6, 32, 14, 10, 2, 12, 2, 2, 12, 36, 6, 28, 6, 12, 32, 8, 12, 28, 24, 48

Offset: 0

Author

Jonathan Vos Post, Feb 05 2006

Keywords

• easy
• nonn

Comments

A098147 is difference between first odd semiprime > 10^n and 10^n.

Examples

			a(0) = 8 because 11^0 + 8 = 9 = 3^2 is an odd semiprime.
a(1) = 4 because 11^1 + 4 = 15 = 3 * 5 is an odd semiprime.
a(2) = 2 because 11^2 + 2 = 123 = 3 * 41.
a(3) = 2 because 11^3 + 2 = 1333 = 31 * 43 (brilliant).
a(4) = 6 because 11^4 + 6 = 14647 = 97 * 151.
a(5) = 14 because 11^5 + 14 = 161065 = 5 * 32213.
a(6) = 4 because 11^6 + 4 = 1771565 = 5 * 354313.
a(7) = 6 because 11^7 + 6 = 19487177 = 41 * 475297.
a(8) = 6 because 11^8 + 6 = 214358887 = 317 * 676211.
a(9) = 6 because 11^9 + 6 = 2357947697 = 7 * 336849671.
a(10) = 4 because 11^10 + 4 = 25937424605 = 5 * 5187484921.
a(30) = 48 because 11^30 + 48 = 17449402268886407318558803753849 = 7 * 2492771752698058188365543393407.
		

Crossrefs

Cf. A001020, A001358, A098147.

Formula

a(n) = minimum integer k such that 11^n + k is an element of A046315. a(n) = minimum integer k such that A001020(n) + k is an element of A046315.