A186257 a(n) = 5*b_5(n)+4, where b_5 lists the indices of zeros of the sequence A261305: u(n) = abs(u(n-1)-gcd(u(n-1),5*n-1)), u(1) = 1.
14, 89, 479, 2879, 17099, 99839, 599009, 3592859, 21557099, 129336149, 775914479, 4655486369, 27932918219, 167597509319, 1005582321329, 6033492323549, 36200953941059, 217205705087639, 1303234230378959, 7819405361540219
Offset: 1
Keywords
Links
- B. Cloitre, 10 conjectures in additive number theory, preprint arxiv:2011.4274 (2011).
- M. F. Hasler, Rowland-Cloître type prime generating sequences, OEIS Wiki, August 2015.
Programs
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PARI
a=1; m=5; for(n=2, 1e7, a=abs(a-gcd(a, m*n-1)); if(a==0, print1(m*n+m-1, ", ")))
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PARI
m=5; a=k=1; for(n=1, 25, while( a>D=vecmin(apply(p->a%p, factor(N=m*(k+a)+m-1)[, 1])), a-=D+gcd(a-D, N); k+=1+D); k+=a+1; print1(a=N, ", ")) \\ M. F. Hasler, Aug 22 2015
Formula
We conjecture that a(n) is asymptotic to c*6^n with c>0.
See the wiki link for a sketch of a proof of this conjecture. More precisely we find c = 1.15917467761... - M. F. Hasler, Aug 22 2015
Extensions
Edited by M. F. Hasler, Aug 14 2015
More terms from M. F. Hasler, Aug 22 2015
Comments