This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
Brandon Crofts has authored 3 sequences.
df:= proc(n) local t, s, m0, m;
if n mod 7 = 0 then
m:= n/7;
t:= 4*nops(select(s -> s < n and s > m, numtheory:-divisors(7*m^2)))
else t:= 0
fi;
m0:= mul(`if`(s[1]=7, s[1]^ceil((s[2]-1)/2),
s[1]^ceil(s[2]/2)), s=ifactors(n)[2]);
t + 4 + 8*floor(n/m0/7);
end proc:
df(0):= 1:
ListTools:-PartialSums(map(df, [$0..100])); # Robert Israel, Jul 01 2020
df:= proc(n) local t,s,m0,m;
if n mod 5 = 0 then
m:= n/5;
t:= 4*nops(select(s -> s < n and s > m, numtheory:-divisors(5*m^2)))
else t:= 0
fi;
m0:= mul(`if`(s[1]=5, s[1]^ceil((s[2]-1)/2),
s[1]^ceil(s[2]/2)),s=ifactors(n)[2]);
t + 4 + 8*floor(n/m0/5);
end proc:
df(0):= 1:
ListTools:-PartialSums(map(df,[$0..100])); # Robert Israel, Jun 29 2020
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