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A129196 a(n)=denominator(3(3+(-1)^n)/(n+1)^3);. 5
1, 4, 9, 32, 125, 36, 343, 256, 243, 500, 1331, 288, 2197, 1372, 1125, 2048, 4913, 972, 6859, 4000, 3087, 5324, 12167, 2304, 15625, 8788, 6561, 10976, 24389, 4500, 29791, 16384, 11979, 19652, 42875, 7776 (list; graph; refs; listen; history; internal format)
OFFSET

0,2

COMMENTS

Numerator of 3(3+(-1)^n)/(n+1)^3 is A129197.

(1/(2*pi))*int(exp(i*(n+1)*t)((t-pi)/i)^3,t,0,2*pi))=(A129202(n)*pi^2-A129203(n))/A129196(n), i=sqrt(-1).

FORMULA

a(n)=A129204(n+1)/(5/3+(4/3)*cos(2*pi*(n+1)/3));

a(n)=denominator((1/(2*pi))*int(exp(i*(n+1)*t)((t-pi)/i)^3,t,0,2*pi)), i=sqrt(-1);

a(n)=denominator((pi^2*(n+1)^2-6)/(n+1)^3);

a(n)=((n+1)^3/(gcd(n+1,2)*gcd(n+1,3))); - Paul Barry (pbarry(AT)wit.ie), Oct 09 2007

a(n)=numerator of coefficient of x^6 in the Maclaurin expansion of -exp(-(n+1)*x^2). [From Francesco Daddi, Aug 04 2011]

CROSSREFS

Sequence in context: A149119 A149120 A057819 * A119574 A006393 A076966

Adjacent sequences:  A129193 A129194 A129195 * A129197 A129198 A129199

KEYWORD

easy,frac,nonn

AUTHOR

Paul Barry (pbarry(AT)wit.ie), Apr 02 2007, Apr 03 2007

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Last modified February 15 15:14 EST 2012. Contains 205823 sequences.