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A240974
Numbers of the form x^y - x*y for x > 1 and y > 1.
1
0, 2, 3, 8, 15, 18, 22, 24, 35, 48, 52, 63, 69, 80, 99, 110, 114, 120, 143, 168, 195, 198, 224, 228, 240, 255, 288, 322, 323, 360, 399, 440, 483, 488, 494, 528, 575, 605, 624, 675, 702, 711, 728, 783, 840, 899, 960, 970, 1004, 1023, 1088, 1155, 1224, 1272, 1295, 1298, 1368, 1443
OFFSET
1,2
COMMENTS
Primes of the form a(k)-1: 2, 7, 17, 23, 47, 79, 109, 167, 197, 223, 239, 359, 439, 487, 701, 727, 839, 1087, 1223, 1297, 1367, ...
Numbers that occur in more than one way include 4^n - 4*n = 2^(2*n) - 2*(2*n). Are those all? - Robert Israel, Jul 21 2024
LINKS
EXAMPLE
0 is in this sequence because 2^2 - 2*2 = 0 for x = 2 > 1 and y = 2 > 1.
MAPLE
N:= 10000: # for terms <= N
R:= {}:
for y from 2 while 2^y - 2*y <= N do
for x from 2 do
v:= x^y - x*y;
if v > N then break fi;
R:= R union {v};
od od:
sort(convert(R, list)); # Robert Israel, Jul 21 2024
CROSSREFS
Sequence in context: A238778 A004731 A135354 * A356879 A293688 A285223
KEYWORD
nonn
AUTHOR
STATUS
approved