A277186 Sum of primes within 2n-wide closed interval centered upon prime(n).

5, 10, 17, 26, 31, 67, 83, 83, 119, 139, 161, 228, 281, 281, 341, 408, 474, 553, 546, 635, 635, 780, 824, 1092, 954, 1008, 1008, 1139, 1197, 1336, 1621, 1687, 1650, 1823, 1854, 1854, 2238, 2634, 2507, 2587, 2450, 2673, 3223, 3223, 3403, 3403, 3591, 4054, 4054, 4331, 4535, 4535, 4828, 4444, 4666

Offset

1,1

Comments

a(n) is the sum of primes within the closed interval [prime(n)-n, prime(n)+n], where prime(n) is the n-th prime.

Links

Table of n, a(n) for n=1..55.

Example

a(3) = 2 + 3 + 5 + 7 = 17; starting at prime(3) = 5, subtract 3 and add 3 to obtain the interval 2 through 8, and then add up the primes within that interval, inclusive of the endpoints of the interval.

Mathematica

Table[Total@ Select[Range[Prime@ n - n, Prime@ n + n], PrimeQ], {n, 55}] (* Michael De Vlieger, Oct 04 2016 *)

Prog

(PARI) a(n) = sum(k=prime(n)-n, prime(n)+n, isprime(k)*k); \\ Michel Marcus, Nov 01 2016

Crossrefs

Cf. A000040, A014688, A014689, A061397.

Sequence in context: A061409 A342553 A229997 * A193053 A340047 A098749

Adjacent sequences: A277183 A277184 A277185 * A277187 A277188 A277189

Keyword

nonn,easy

Author

Walter Carlini, Oct 04 2016

Extensions

More terms from Michael De Vlieger, Oct 04 2016

Status

approved