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A323542
a(n) = Product_{k=0..n} (k^4 + (n-k)^4).
15
0, 1, 512, 1896129, 14101250048, 242755875390625, 7888809923487203328, 452522453429009743939201, 42521926771106843499966758912, 6212193882217859346149080691430849, 1350441156698962215630405632000000000000, 421551664651621436548685508587919503984205889
OFFSET
0,3
LINKS
FORMULA
a(n) ~ exp((Pi*(sqrt(2) - 1/2) - 4)*n) * n^(4*n + 4).
MATHEMATICA
Table[Product[k^4+(n-k)^4, {k, 0, n}], {n, 0, 15}]
PROG
(Magma) [(&*[(k^4 + (n-k)^4): k in [0..n]]): n in [0..15]]; // Vincenzo Librandi, Jan 18 2019
(PARI) m=4; vector(15, n, n--; prod(k=0, n, k^m + (n-k)^m)) \\ G. C. Greubel, Jan 18 2019
(Sage) m=4; [product(k^m +(n-k)^m for k in (0..n)) for n in (0..15)] # G. C. Greubel, Jan 18 2019
CROSSREFS
Cf. 2*A000538 and A259108 (with sum instead of product).
Sequence in context: A320861 A347858 A220303 * A016797 A013789 A330484
KEYWORD
nonn
AUTHOR
Vaclav Kotesovec, Jan 17 2019
STATUS
approved