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A377082
a(0) = 1, a(1) = 3, a(2) = 13; for n >= 2, a(n+1) = 2*3^((a(n)-1)/4) - 1.
0
1, 3, 13, 53, 3188645
OFFSET
0,2
COMMENTS
The next term is too large to include.
a(n) is the least positive integer that requires n steps to reach 1 under iteration of the sum of squares of digits function in base 3 (A006287).
a(n) is also the least positive integer that requires n steps to reach 1 under iteration of the map A375212.
LINKS
N. Bradley Fox et al., Elated Numbers, arXiv:2409.09863 [math.NT], 2024.
G. Lapointe, On finding the smallest happy numbers of any heights, arXiv:1904.12032 [math.NT], 2019.
CROSSREFS
KEYWORD
nonn
AUTHOR
N. Bradley Fox, Nathan Fox, Helen Grundman, Rachel Lynn, Changningphaabi Namoijam, Mary Vanderschoot, Oct 15 2024
STATUS
approved