login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Decades with the same semiprime pattern as the next decade.
2

%I #10 Oct 17 2016 02:19:32

%S 102,387,433,436,527,656,882,1108,1181,1531,1546,1555,1667,1797,1822,

%T 1823,1913,1991,2009,2074,2083,2151,2311,2353,2370,2615,2626,2646,

%U 2671,3202,3232,3256,3278,3293,3371,3413,3511,3599,3634,3904,3929,3934,4123,4152

%N Decades with the same semiprime pattern as the next decade.

%F a(n) = A220063(n)-2.

%F a(n) = A277460(n)-1.

%e a(1)=102 because the decade from 1020 to 1029 has the same semiprime pattern as the decade from 1030 to 1039 (1027 and 1037).

%Y Cf. A220063, A277460.

%K nonn

%O 1,1

%A _Bobby Jacobs_ and _N. J. A. Sloane_, Oct 16 2016