A073566 Numbers n such that n, n+1 and n+2 have the same number of anti-divisors.

19, 74, 90, 102, 148, 187, 204, 212, 213, 231, 232, 233, 328, 329, 351, 457, 469, 519, 546, 547, 555, 573, 756, 859, 868, 869, 870, 879, 980, 981, 991, 1025, 1080, 1081, 1096, 1120, 1121, 1122, 1132, 1158, 1211, 1413, 1420, 1430, 1431, 1441, 1467, 1482

Offset

1,1

Comments

See A066272 for definition of anti-divisor.

Links

Table of n, a(n) for n=1..48.

Mathematica

at[n_] := Count[Flatten[Quotient[#, Rest[Select[Divisors[#], OddQ]]] & /@ (2 n + Range[-1, 1])], Except[1]]; Select[Range[1485], at[#] == at[# + 1] == at[# + 2] &] (* Jayanta Basu, Jul 01 2013 *)

Crossrefs

Cf. A066272.

Sequence in context: A373668 A290241 A159997 * A098467 A244631 A304513

Adjacent sequences: A073563 A073564 A073565 * A073567 A073568 A073569

Keyword

nonn

Author

Jason Earls, Aug 31 2002

Status

approved