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1, 6, 15, 32, 50, 84, 112, 160, 207, 270, 319, 420, 481, 574, 675, 800, 884, 1044, 1140, 1320, 1470, 1628, 1748, 2016, 2175, 2366, 2565, 2828, 2987, 3330, 3503, 3808, 4059, 4318, 4585, 5040, 5254, 5548, 5850, 6320, 6560, 7056, 7310, 7744, 8190, 8556, 8836
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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1,2
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LINKS
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FORMULA
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EXAMPLE
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a(4) = 32 = sum of row 4 terms of triangle A143273: (4 + 8 + 8 + 12).
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PROG
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(Python)
from math import isqrt
def A143274(n): return (-(s:=isqrt(n))**2+(sum(n//k for k in range(1, s+1))<<1))*n # Chai Wah Wu, Oct 23 2023
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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