

A001273


Smallest number that takes n steps to reach 1 under iteration of sumofsquaresofdigits map (= smallest "happy number" of height n).


6




OFFSET

0,2


COMMENTS

Subsequent terms are too large to display in full.
a(8) = 3789 * 10^973  1 (3788 followed by 973 9's).
a(9) = 78889 * 10^((a(8)  305)/81)  1 (78888 followed by (421 * 10^973  34)/9 9's, specified by Warut Roonguthai for UPINT3).
a(10) = 259 * 10^((a(9)  93)/81)  1.
a(11) = 179 * 10^((a(10)  114)/81)  1.
a(12) = 47 * 10^((a(11)  52)/81)  1.


REFERENCES

Richard K. Guy, Unsolved Problems in Number Theory, Sect. E34. (2nd ed. UPINT2 = 1994, 3rd ed. UPINT3 = 2004)


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CROSSREFS



KEYWORD

nonn,base


AUTHOR



EXTENSIONS



STATUS

approved



