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%I #7 Mar 30 2012 17:34:04
%S 1,121,141,161,171,1241,1251,1261,1271,1281,1341,1351,1371,1391,1421,
%T 1431,1461,1491,1521,1541,1561,1581,1591,1631,1641,1651,1671,1681,
%U 1691,1731,1751,1761,1781,1791,1821,1841,1851,1891,1921,1941,1961,1971,1981,12321,12341,12351,12361,12371
%N Mountain nonprimes.
%C The total number of terms is 19226. The largest is 12345678987654321 which is also the largest Giza number A134810.
%F A018252 INTERSECT A134941.
%e a(2)=121 is in the sequence because 121 is a nonprime number A018252 and 121 is also a mountain number A134941.
%e Illustration of 134961 as a mountain nonprime:
%e . . . 9 . .
%e . . . . . .
%e . . . . . .
%e . . . . 6 .
%e . . . . . .
%e . . 4 . . .
%e . 3 . . . .
%e . . . . . .
%e 1 . . . . 1
%Y Cf. A018252, A134810, A134941, A134951.
%K nonn,base,fini
%O 1,2
%A _Omar E. Pol_, Dec 14 2010