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Let R(n) = sum {k = 0..inf} (3k)^n/(3k)! for n = 0,1,2,... . Then the real number R(n) is an integral linear combination of R(0), R(1) and R(2). This sequence gives the coefficients of R(1).
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%I #11 Jun 28 2017 20:27:17

%S 0,1,0,-2,-5,-5,20,149,552,991,-3799,-49841,-299937,-1127358,-587744,

%T 34873758,380671819,2584563448,11105613358,-2623056379,-659822835085,

%U -8393151852216,-69959106516419,-390297675629170,-414406919999723

%N Let R(n) = sum {k = 0..inf} (3k)^n/(3k)! for n = 0,1,2,... . Then the real number R(n) is an integral linear combination of R(0), R(1) and R(2). This sequence gives the coefficients of R(1).

%C The coefficients of R(0) and R(2) are listed in A143815 and A143817 respectively.

%F a(n) = A143816(n) - A143817(n). a(n) = sum {k = 0..floor((n-1)/3)} (Stirling2(n,3k+1) - Stirling2(n,3k+2)). Let R(n) = sum {k = 0..inf} (3k)^n/(3k)! for n = 0,1,2,... . Then R(n) = A143815(n)*R(0) + A143818(n)*R(1) + A143817(n)*R(2). Some examples are given below. This generalizes the Dobinski relation for the Bell numbers: sum {k = 0..inf} k^n/k! = A000110(n)*exp(1). See A143815 for more details. Compare with A024429, A024430 and A143628--A143631

%e R(n) as a linear combination of R(i),

%e i = 0..2.

%e ====================================

%e ..R(n)..|.....R(0)....R(1)....R(2)..

%e ====================================

%e ..R(3)..|.......1......-2.......3...

%e ..R(4)..|.......6......-5.......7...

%e ..R(5)..|......25......-5......16...

%e ..R(6)..|......91......20......46...

%e ..R(7)..|.....322.....149.....203...

%e ..R(8)..|....1232.....552....1178...

%e ..R(9)..|....5672.....991....7242...

%e ..R(10).|...32202...-3799...43786...

%e ...

%p M:=24: a:=array(0..100): b:=array(0..100): c:=array(0..100):

%p a[0]:=1: b[0]:=0: c[0]:=0:

%p for n from 1 to M do

%p a[n]:=add(binomial(n-1,k)*b[k], k=0..n-1);

%p b[n]:=add(binomial(n-1,k)*c[k], k=0..n-1);

%p c[n]:=add(binomial(n-1,k)*a[k], k=0..n-1);

%p end do:

%p A143818:=[seq(b[n]-c[n], n=0..M)];

%t m = 24; a[0] = 1; b[0] = 0; c[0] = 0; For[n = 1, n <= m, n++, a[n] = Sum[Binomial[n - 1, k]*b[k], {k, 0, n - 1}]; b[n] = Sum[Binomial[n - 1, k]*c[k], {k, 0, n - 1}]; c[n] = Sum[Binomial[n - 1, k]*a[k], {k, 0, n - 1}] ]; A143818 = Table[c[n] - b[n], {n, 0, m}] (* _Jean-François Alcover_, Mar 06 2013, after Maple *)

%Y A000110, A024429, A024430, A143628, A143629, A143630, A143631, A143815, A143816, A143817.

%K easy,sign

%O 1,4

%A _Peter Bala_, Sep 03 2008

%E Spelling/notation corrections by _Charles R Greathouse IV_, Mar 18 2010