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A099186 Iterated icosahedral numbers: a(0)=1, a(1) = 12, a(n+1)=A006564(a(n)). 1
1, 12, 3972, 156624027132, 9605393649115032262909140007773492, 2215570185245038872814956021479696635481690776469126111743280383568619886232750745465064720338596867052 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

This starts at a(1)=A006564(2)=12. An alternative, for example: if a(1) were set to A006564(3) = 48,

then a(2) = A006564(48) = 270768, a(3) = A006564(270768) = 49628416238058288;

a(4) = A006564(49628416238058288) = 305584454132546884153602392143848716431702444690608 etc.

REFERENCES

Conway, J. H. and Guy, R. K. The Book of Numbers. New York: Springer-Verlag, p. 50, 1996.

J. V. Post, "Iterated Triangular Numbers", preprint.

LINKS

Table of n, a(n) for n=0..5.

H. K. Kim, On Regular Polytope Numbers, Proc. Amer. Math. Soc. 131 (2003), 65-75. MR 1929024

J. V. Post, Table of Polytope Numbers, Sorted, Through 1,000,000.

EXAMPLE

a(2) = A006564(a(1)) = A006564(12) = 12*(5*12^2 - 5*12 + 2)/2 = 3972.

CROSSREFS

Cf. A007501, A006564.

Sequence in context: A012609 A159395 A272093 * A307944 A105067 A096732

Adjacent sequences:  A099183 A099184 A099185 * A099187 A099188 A099189

KEYWORD

easy,nonn

AUTHOR

Jonathan Vos Post, Nov 15 2004

EXTENSIONS

Definition and comments condensed by R. J. Mathar, Sep 09 2009

STATUS

approved

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Last modified May 16 12:46 EDT 2021. Contains 343947 sequences. (Running on oeis4.)