A143474 a(n) = smallest k such that A141501(k) = 2*n+1.

1, 2, 4, 6, 12, 30, 24, 72, 60, 144, 120, 180, 240, 360, 1008, 720, 1440, 840, 1260, 3780, 7920, 3360, 10920, 2520, 7560, 5040, 10080, 69300, 15120, 864864, 92400, 27720, 60480, 65520, 617760, 240240, 55440, 196560, 110880, 471240, 166320, 6177600

Offset

1,2

Comments

All terms of A141501 are odd.

Links

Klaus Brockhaus, Table of n, a(n) for n=1..69

Example

First few terms of A141501 are 3, 5, 5, 7, 3, 9, 3, 7, 5, 7, 3, 11, ..., so a(1) to a(5) are 1, 2, 4, 6, 12.

Prog

(PARI) {m=6200000; z=42; v=vector(z); for(n=1, m, k=1; d=divisors(n); while(1, c=0; for(j=1, #d, if(d[j]<=k, c++)); if(k-c<=c, k++, break)); i=(k-1)/2; if(i<=z&&v[i]<1, v[i]=n)); j=1; while(j<=z&&v[j]>0, print1(v[j], ", "); j++)}

Crossrefs

Cf. A141501.

Sequence in context: A118405 A332345 A095912 * A261341 A220423 A335068

Adjacent sequences: A143471 A143472 A143473 * A143475 A143476 A143477

Keyword

nonn

Author

Klaus Brockhaus, Aug 21 2008

Status

approved