A024214 a(n) = 4th elementary symmetric function of first n+3 positive integers congruent to 1 mod 3.

280, 5714, 45474, 227969, 859369, 2662569, 7141953, 17147823, 37702863, 77161513, 148781633, 272796342, 479082422, 810530182, 1327228182, 2111584722, 3274516506, 4962843396, 7368036676, 10736476751, 15381384711, 21696600695

Offset: 1

Author

Clark Kimberling

Keywords

• nonn
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..10000
• Index entries for linear recurrences with constant coefficients, signature (9,-36,84,-126,126,-84,36,-9,1).

Programs

Magma

[n*(n+1)*(n+2)*(n+3)*(405*n^4+3510*n^3+9855*n^2+8814*n-184)/1920: n in [1..30]]; // Vincenzo Librandi, Oct 10 2011

Formula

a(n) = n*(n+1)*(n+2)*(n+3)*(405*n^4+3510*n^3+9855*n^2+8814*n-184)/1920.

G.f. -x*(280+3194*x+4128*x^2+887*x^3+16*x^4) / (x-1)^9 . - R. J. Mathar, Oct 08 2011