A281599 Numbers k such that A000005(k) = A000005(A000041(k)).

1, 2, 3, 5, 8, 13, 42, 56, 65, 87, 93, 95, 102, 108, 114, 123, 143, 146, 157, 161, 190, 195, 198, 200, 203, 210, 218, 234, 235, 238, 266, 275, 287, 312, 321, 370, 375, 380, 385, 410, 416, 437, 475, 491, 513, 568, 572, 582, 590, 626, 627, 636, 660, 685, 702

Offset

1,2

Comments

Numbers k such that the number of divisors of k is equal to the number of divisors of the number of partitions of k.

Links

Charles R Greathouse IV and Amiram Eldar, Table of n, a(n) for n = 1..500 (terms 1..225 from Charles R Greathouse IV)

Mathematica

Select[Range[1500], DivisorSigma[0, #] == DivisorSigma[0, PartitionsP[#]] &] (* Indranil Ghosh, Mar 09 2017 *)

Prog

(PARI) select(n->numdiv(n)==numdiv(numbpart(n)), vector(750, n, n))

Crossrefs

Cf. A000005, A000041, A281597, A281598.

Sequence in context: A273045 A014259 A001129 * A041957 A329192 A294939

Adjacent sequences: A281596 A281597 A281598 * A281600 A281601 A281602

Keyword

nonn

Author

Colin Barker, Jan 25 2017

Status

approved