OFFSET
1,1
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..2611
MATHEMATICA
SequencePosition[Table[DivisorSigma[0, Binomial[2n, n]], {n, 1000}], {x_, x_}][[All, 2]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Apr 15 2019 *)
PROG
(PARI) lista(nn) = my(last = 0); for (i=1, nn, new = numdiv(binomial(2*i, i)); if (last == new, print1(i, ", ")); last = new) \\ Michel Marcus, Aug 21 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
Michel Marcus, Aug 21 2013
STATUS
approved