cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A365493 a(n) is the smallest number which can be represented as the sum of n n-almost primes in exactly n ways, or -1 if no such number exists.

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%I A365493 #24 Jun 12 2025 14:30:17
%S A365493 2,18,44,112,418,776,1408,3072,7040,14848,53056,77312,147456,315392,
%T A365493 988160,5310464,3194880,6225920,12845056,46252032,76873728,117440512,
%U A365493 258998272,1072824320,1111490560,3379560448,5192548352,9261023232,24243077120,41204842496,81067507712
%N A365493 a(n) is the smallest number which can be represented as the sum of n n-almost primes in exactly n ways, or -1 if no such number exists.
%H A365493 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/AlmostPrime.html">Almost Prime</a>.
%e A365493 For n = 2: 18 = 2*2 + 2*7 = 3*3 + 3*3.
%Y A365493 Cf. A091538, A365494.
%K A365493 nonn
%O A365493 1,1
%A A365493 _Ilya Gutkovskiy_, Sep 07 2023
%E A365493 More terms from _David A. Corneth_, Jun 12 2025