A075895 Rounded sum of first n odd integers squared divided by n-th prime.

0, 3, 7, 12, 15, 22, 27, 36, 42, 46, 57, 62, 71, 85, 96, 103, 111, 127, 136, 150, 169, 180, 195, 207, 215, 232, 255, 273, 298, 318, 313, 333, 350, 377, 384, 412, 430, 449, 474, 493, 513, 546, 555, 588, 617, 652, 656, 661, 691, 728, 759, 784, 824, 836, 863, 890, 918, 960, 989, 1025, 1069, 1084, 1086

Offset

1,2

Comments

a(n) is integer (presumably) only for n = 3, 4, 5, 6; corresponding values for a(n) = 7, 12, 15, 22.

Links

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

Formula

a(n) = round(n*(4n^2 - 1)/(3*prime(n))) for n>=2, a(1) = 0.

Maple

0, seq(round(n*(4*n^2-1)/(3*ithprime(n))), n=2..100); # Robert Israel, Jul 06 2017

Crossrefs

Sequence in context: A310235 A310236 A296094 * A033015 A225574 A317305

Adjacent sequences: A075892 A075893 A075894 * A075896 A075897 A075898

Keyword

easy,nonn

Author

Zak Seidov, Oct 17 2002

Extensions

a(44)-a(63) from Robert Israel, Jul 06 2017

Status

approved