A365493 - OEIS

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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.

1

2, 18, 44, 112, 418, 776, 1408, 3072, 7040, 14848, 53056, 77312, 147456, 315392, 988160, 5310464, 3194880, 6225920, 12845056, 46252032, 76873728, 117440512, 258998272, 1072824320, 1111490560, 3379560448, 5192548352, 9261023232, 24243077120, 41204842496, 81067507712

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OFFSET

1,1

LINKS

Table of n, a(n) for n=1..31.

Eric Weisstein's World of Mathematics, Almost Prime.

EXAMPLE

For n = 2: 18 = 2*2 + 2*7 = 3*3 + 3*3.

CROSSREFS

Cf. A091538, A365494.

Sequence in context: A393285 A072278 A296266 * A280316 A131538 A009820

Adjacent sequences: A365490 A365491 A365492 * A365494 A365495 A365496

KEYWORD

nonn

AUTHOR

Ilya Gutkovskiy, Sep 07 2023

EXTENSIONS

More terms from David A. Corneth, Jun 12 2025

STATUS

approved