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7, 26, 124, 342, 1330, 2196, 12166, 24388, 29790, 79506, 103822, 148876, 205378, 226980, 300762, 357910, 493038, 571786, 1030300, 1092726, 1225042, 2248090, 2685618, 3307948, 3442950, 3869892, 4657462, 5177716, 5735338, 6967870, 7645372, 9393930, 11089566, 11697082
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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1,1
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LINKS
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EXAMPLE
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MATHEMATICA
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f[p_, e_] := If[e < 3, p^e, p^e - p^(e - 3)]; s[n_] := Times @@ f @@@ FactorInteger[n]; Select[Range[10^6], s[#] == s[# + 1] &]
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PROG
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(Python)
from math import prod
from itertools import count, islice
from sympy import factorint
def A349309_gen(startvalue=1): # generator of terms >= startvalue
a = prod(p**e - (p**(e-3) if e >= 3 else 0) for p, e in factorint(max(startvalue, 1)).items())
for k in count(max(startvalue, 1)):
b = prod(p**e - (p**(e-3) if e >= 3 else 0) for p, e in factorint(k+1).items())
if a == b:
yield k
a = b
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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