login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A073435
Smallest x such that remainder if x-th composite is divided by pi(x) equals n.
3
4, 7, 8, 13, 30, 17, 35, 23, 40, 50, 53, 51, 55, 52, 63, 60, 68, 69, 146, 76, 154, 83, 156, 162, 172, 177, 185, 109, 195, 187, 192, 188, 189, 190, 208, 209, 210, 214, 215, 216, 217, 230, 218, 219, 220, 224, 225, 251, 248, 249, 250, 255, 256, 262, 267, 280, 289
OFFSET
1,1
LINKS
FORMULA
a(n) = Min{x; Mod[A002808(x), A000720(x)]=n} = Min{x; A065861(x)=n}.
EXAMPLE
Remainder=4 appears first as Mod[c[13],Pi[13]]=Mod[22,6]=4, so a(4)=13.
MAPLE
N:= 100: m:= 1: V:= Vector(N): count:= 0:
for n from 6 while count < N do
if not isprime(n) then
m:= m+1;
t:= n mod numtheory:-pi(m);
if t > 0 and t <= N and V[t] = 0 then
count:= count+1; V[t]:= m
fi
fi
od:
convert(V, list); # Robert Israel, May 21 2020
CROSSREFS
KEYWORD
nonn,look
AUTHOR
Labos Elemer, Jul 31 2002
STATUS
approved