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Largest unsigned Stirling number of the first kind: max_k(s(n+1,k)); i.e., largest coefficient of polynomial x*(x+1)*(x+2)*(x+3)*...*(x+n).
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%I #37 Feb 01 2024 00:28:01

%S 1,1,3,11,50,274,1764,13132,118124,1172700,12753576,150917976,

%T 1931559552,26596717056,392156797824,6165817614720,102992244837120,

%U 1821602444624640,34012249593822720,668609730341153280,13803759753640704000,298631902863216384000

%N Largest unsigned Stirling number of the first kind: max_k(s(n+1,k)); i.e., largest coefficient of polynomial x*(x+1)*(x+2)*(x+3)*...*(x+n).

%C n! <= a(n) <= (n+1)!; n <= a(n+1)/a(n) <= (n+1). - _Max Alekseyev_, Jul 17 2019

%H Robert Israel, <a href="/A065048/b065048.txt">Table of n, a(n) for n = 0..448</a>

%F For n in the interval [A309237(k)-1, A309237(k+1)-2], a(n) = |Stirling1(n+1,k)|. - _Max Alekseyev_, Jul 17 2019

%e a(4)=50 since polynomial is x^4 + 10*x^3 + 35*x^2 + 50*x + 24.

%p P:= x: A[0]:= 1:

%p for n from 1 to 50 do

%p P:= expand(P*(x+n));

%p A[n]:= max(coeffs(P,x));

%p od:

%p seq(A[i],i=0..50); # _Robert Israel_, Jul 04 2016

%t a[n_] := Max[Array[Abs[StirlingS1[n+1, #]]&, n+1]];

%t Array[a, 100, 0] (* _Griffin N. Macris_, Jul 03 2016 *)

%o (PARI) a(n) = if (n==0, 1, vecmax(vector(n, k, abs(stirling(n+1, k, 1))))); \\ _Michel Marcus_, Jul 04 2016; corrected Jun 12 2022

%o (Python)

%o from collections import Counter

%o def A065048(n):

%o c = {1:1}

%o for k in range(1,n+1):

%o d = Counter()

%o for j in c:

%o d[j] += k*c[j]

%o d[j+1] += c[j]

%o c = d

%o return max(c.values()) # _Chai Wah Wu_, Jan 31 2024

%Y Cf. A000254, A000399, A008275, A309237.

%K nonn

%O 0,3

%A _Henry Bottomley_, Nov 06 2001