A116033 Numbers k such that sigma(k) plus the k-th prime is a prime.

1, 5, 10, 11, 14, 15, 20, 23, 24, 28, 29, 34, 35, 38, 39, 40, 42, 44, 46, 48, 52, 56, 57, 59, 60, 62, 65, 66, 68, 69, 74, 75, 76, 82, 85, 87, 92, 95, 97, 102, 106, 109, 114, 118, 119, 120, 122, 124, 126, 133, 136, 137, 139, 143, 145, 146, 148, 149, 152, 153, 156

Offset

1,2

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Example

sigma(145)+prime(145) = 1009 (prime).

Maple

select(k -> isprime(numtheory:-sigma(k) + ithprime(k)), [$1..1000]); # Robert Israel, Aug 18 2024

Mathematica

Select[Range[156], PrimeQ[DivisorSigma[1, #]+Prime[#]]&] (* James C. McMahon, Aug 18 2024 *)

Crossrefs

Cf. A116034.

Sequence in context: A004748 A038030 A094016 * A290469 A375320 A140507

Adjacent sequences: A116030 A116031 A116032 * A116034 A116035 A116036

Keyword

nonn

Author

Giovanni Resta, Feb 13 2006

Status

approved