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%I #6 Jan 17 2023 16:31:18
%S 1,2,4,8,56,108,5536,28074040,39648,147312,18566888967365603514688,
%T 9966792788887776,2775641472,2505471397838180985096739296,
%U 1445523368993397560000765219760086502994234237205516083525719052320,44092571484448511101335177770183225655413760
%N a(n) is the smallest tetranacci number (A000078) with exactly n prime factors (counted with multiplicity).
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/PrimeFactor.html">Prime Factor</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/TetranacciNumber.html">Tetranacci Number</a>
%e a(6) = 5536, because 5536 is a tetranacci number with 6 prime factors (counted with multiplicity) {2, 2, 2, 2, 2, 173} and this is the smallest such number.
%Y Cf. A000078, A001222, A072397, A359849, A359876, A359879.
%K nonn
%O 0,2
%A _Ilya Gutkovskiy_, Jan 16 2023