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A337055
Numbers that are k+A000010(k) for at least two different k.
1
24, 32, 33, 38, 45, 48, 56, 64, 76, 86, 93, 96, 112, 113, 128, 140, 150, 152, 153, 172, 182, 192, 200, 203, 213, 216, 224, 225, 231, 256, 258, 263, 280, 293, 297, 300, 304, 320, 325, 326, 333, 342, 344, 345, 352, 364, 374, 380, 383, 384, 393, 397, 400, 402, 410, 413, 429, 432, 448, 459, 470, 473
OFFSET
1,1
COMMENTS
If p>2 and 4*p-1 are prime, then 12*p-4 is in the sequence.
If p>3 and (5*p-1)/2 are prime, then 5*p-2 is in the sequence.
LINKS
EXAMPLE
a(3)=33 is in the sequence because 33 = 17 + A000010(17) = 21 + A000010(21).
MAPLE
N:= 20000: # for terms <= N
V:= Vector(N):
for n from 1 to N do
v:= n + numtheory:-phi(n);
if v <= N then V[v]:= V[v]+1 fi
od:
select(t -> V[t]>=2, [$1..N]);
CROSSREFS
Sequence in context: A266984 A217158 A214227 * A064673 A034782 A289554
KEYWORD
nonn
AUTHOR
J. M. Bergot and Robert Israel, Aug 12 2020
STATUS
approved