A137532 a(n) is the smallest positive integer k such that d(k) = d(k+n) = 2*n, where d(m) (A000005) is the number of positive divisors of m, or 0 if no such k exists.
2, 6, 172, 66, 15952, 84, 22592, 888, 2196, 3750, 459932661, 660, 86817796083, 185152, 143366096, 5304, 17685013528576, 3150, 1786574475624429, 1272510, 29059703104, 12872682, 4817557477673402368, 9576, 85608255863, 15744471040, 1179648, 124718750, 1765038427619364800823267
Offset: 1
Keywords
Programs
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PARI
lq080419b(n,a)=n*=2; until(0,numdiv(a++)==n || next; numdiv(a+n\2)==n && break); a for(i=1,99,print1(lq080419b(i)", "))
Extensions
a(11) from Jacques Tramu, Apr 20 2008
More terms from Jinyuan Wang, May 08 2021