OFFSET
1,2
REFERENCES
L. E. Dickson, History of the Theory of Numbers. Carnegie Institute Public. 256, Washington, DC, Vol. 1, 1919; Vol. 2, 1920; Vol. 3, 1923, see vol. 2, p. 22.
LINKS
Index entries for linear recurrences with constant coefficients, signature (195, -195, 1).
FORMULA
EXAMPLE
15*x^2 + 2926*x^3 + 567645*x^4 + 110120220*x^5 + 21362755051*x^6 + ...
a(4) = 567645 which is 1065*(1065-1)/2 = 615*(3*615+1)/2.
PROG
(PARI) {a(n) = polchebyshev( 2*n - 2, 2, 7) / 14 + polchebyshev( 2*n - 2, 1, 7) / 84 - 1 / 12} /* Michael Somos, Jun 16 2011 */
CROSSREFS
KEYWORD
nonn
AUTHOR
Michael Somos, May 30 2005
STATUS
approved