login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

a(n) = (5^n - 4^n + 3^n - 2^n)/2.
1

%I #11 Jan 05 2021 21:33:00

%S 0,1,7,40,217,1156,6097,31900,165697,855076,4387537,22404460,

%T 113945377,577590196,2919923377,14729076220,74167952257,372944296516,

%U 1873182473617,9399885079180,47135702874337,236224784974036

%N a(n) = (5^n - 4^n + 3^n - 2^n)/2.

%C Binomial transform of A053154 (with leading zero).

%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (14,-71,154,-120).

%F G.f.: x(1-7x+13x^2)/((1-2x)(1-3x)(1-4x)(1-5x)).

%F E.g.f.: exp(5x) - exp(4x) + exp(3x) - exp(2x).

%F a(n) = 14*a(n-1) - 71*a(n-2) + 154*a(n-3) - 120*a(n-4), n > 3. - _Harvey P. Dale_, Apr 04 2013

%t Table[(5^n-4^n+3^n-2^n)/2,{n,0,30}] (* or *) LinearRecurrence[{14,-71,154,-120},{0,1,7,40},30] (* _Harvey P. Dale_, Apr 04 2013 *)

%Y Cf. A083328.

%K easy,nonn

%O 0,3

%A _Paul Barry_, Apr 27 2003