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A163141 a(n) = 5*a(n-2) for n > 2; a(1) = 4, a(2) = 5. 4
4, 5, 20, 25, 100, 125, 500, 625, 2500, 3125, 12500, 15625, 62500, 78125, 312500, 390625, 1562500, 1953125, 7812500, 9765625, 39062500, 48828125, 195312500, 244140625, 976562500, 1220703125, 4882812500, 6103515625, 24414062500 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

Apparently the same as A133632 without initial 1.

Binomial transform is A163069, second binomial transform is A163070, third binomial transform is A163071, fourth binomial transform is A108404 without initial 1, fifth binomial transform is A163072.

FORMULA

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

G.f.: x*(4+5*x)/(1-5*x^2).

PROG

(MAGMA) [ n le 2 select n+3 else 5*Self(n-2): n in [1..29] ];

CROSSREFS

Cf. A133632, A108404, A163069, A163070, A163071, A163072.

Sequence in context: A080610 A047175 A133632 * A059182 A027958 A064670

Adjacent sequences:  A163138 A163139 A163140 * A163142 A163143 A163144

KEYWORD

nonn

AUTHOR

Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Jul 21 2009

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Last modified February 15 03:33 EST 2012. Contains 205694 sequences.