A074692 1 + n-th prime is harmonic.

3, 34, 57, 259, 428, 806, 15797, 21020, 21395, 116943, 168850, 180159, 329868, 398229, 416148, 1000579, 1453492, 2263664, 3121796, 3366944, 4077320, 5239439, 6334640, 10644940, 15607405, 22504931, 26354609, 27675237, 35041357, 42370771, 46031750, 63585017, 67747753

Offset

1,1

Links

Table of n, a(n) for n=1..33.

Example

1 + prime(34) = 140, which is harmonic, so 34 belongs to the sequence.

Mathematica

isHarmonic[n_] := IntegerQ[n*DivisorSigma[0, n] / DivisorSigma[1, n]]; Select[Range[10^5], isHarmonic[Prime[ # ] + 1] &]

Crossrefs

Cf. A001599.

Sequence in context: A197220 A042821 A110070 * A003348 A344641 A086488

Adjacent sequences: A074689 A074690 A074691 * A074693 A074694 A074695

Keyword

easy,nonn

Author

Joseph L. Pe, Sep 27 2002

Extensions

More terms from Amiram Eldar, Mar 24 2019

Status

approved