A082125 - OEIS

A082125

Smallest difference>1 between d and p/d for any divisor d of the partial product p of the sequence, starting with 4.

4, 3, 4, 2, 4, 8, 16, 64, 512, 16384, 2097152, 2147483648, 140737488355328, 1180591620717411303424, 40564819207303340847894502572032, 365375409332725729550921208179070754913983135744

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OFFSET

0,1

COMMENTS

a(n) is a power of two for n>1 and log_2(a(n))=A073941(n) for n>2. - Ralf Stephan, Apr 16 20.

LINKS

Table of n, a(n) for n=0..15.

R. Stephan, [math/0305348] On a sequence related to the Josephus problem

Index entries for sequences related to the Josephus Problem

PROG

(PARI) p=4; print1(p, ", "); for(n=1, 50, v=divisors(p); r=sqrt(p); t=0; for(k=1, matsize(v)[2], if(v[k]>=r, t=k; break)); if(v[t]^2==p, u=t, u=t-1); if(v[t]-v[u]<2, u=u-1; t=t+1); print1(v[t]-v[u]", "); p=p*(v[t]-v[u]))

CROSSREFS

Cf. A082120, A003681 (starts with 2, 3), A082126.

Cf. A029744.

Sequence in context: A204819 A161882 A276789 * A058290 A356033 A002285

Adjacent sequences: A082122 A082123 A082124 * A082126 A082127 A082128

KEYWORD

nonn,hard

AUTHOR

Ralf Stephan, Apr 04 2003

STATUS

approved