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A085864 a(1) = 2, a(n+1) = a(n)*{tau(a(n))}. 2
2, 4, 12, 72, 864, 20736, 933120, 117573120, 42326323200, 36315985305600, 146426052752179200, 1475974611741966336000, 37784950060594338201600000, 2031318915257551621718016000000, 212719716805770805826310635520000000 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(1) = 1, a(n+1) = a(n) + tau(a(n)) gives A064491.

LINKS

Table of n, a(n) for n=1..15.

EXAMPLE

a(4) = 72 and tau(72)= 12, hence a(5) = 72*12= 864.

PROG

(PARI) for(n=1, 16, if(n==1, a=2, a*=numdiv(a)); print(a); )

CROSSREFS

Cf. A064491.

Sequence in context: A013207 A172165 A078919 * A060935 A141522 A114903

Adjacent sequences:  A085861 A085862 A085863 * A085865 A085866 A085867

KEYWORD

nonn

AUTHOR

Amarnath Murthy, Jul 06 2003

EXTENSIONS

More terms from Ray Chandler, Jul 16 2003

STATUS

approved

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Last modified April 8 05:55 EDT 2020. Contains 333312 sequences. (Running on oeis4.)