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A373686
a(n) is the number of ways n can be written as a sum of a practical number and two squares.
1
1, 2, 2, 2, 2, 4, 2, 3, 3, 4, 3, 4, 3, 4, 2, 4, 5, 5, 4, 6, 6, 6, 2, 6, 5, 7, 4, 7, 7, 6, 5, 7, 9, 7, 4, 8, 9, 10, 2, 9, 10, 9, 6, 9, 9, 8, 5, 8, 10, 9, 5, 10, 11, 9, 7, 12, 11, 11, 6, 9, 11, 10, 3, 11, 14, 13, 9, 12, 13, 11, 7, 10, 15, 14, 4, 13, 13, 8, 8, 15
OFFSET
1,2
COMMENTS
Somu and Tran (2024) proved that a(n) > 0 for sufficiently large n and conjectured that a(n) > 0 for all n > 0. The conjecture was checked up to 10^8.
LINKS
Sai Teja Somu and Duc Van Khanh Tran, On sums of practical numbers and polygonal numbers, Journal of Integer Sequences, 27(5), 2024.
CROSSREFS
Sequence in context: A046927 A366563 A351411 * A084718 A154851 A281854
KEYWORD
nonn
AUTHOR
Duc Van Khanh Tran, Jun 13 2024
STATUS
approved