A227547 a(n) = a(n-1) + prime(n-1), with a(1)=3.

3, 5, 8, 13, 20, 31, 44, 61, 80, 103, 132, 163, 200, 241, 284, 331, 384, 443, 504, 571, 642, 715, 794, 877, 966, 1063, 1164, 1267, 1374, 1483, 1596, 1723, 1854, 1991, 2130, 2279, 2430, 2587, 2750, 2917, 3090, 3269, 3450, 3641, 3834, 4031, 4230, 4441, 4664

Offset: 1

Author

Vincenzo Librandi, Jul 27 2013

Keywords

• nonn
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A007504, A014284, A036439.

Programs

Magma

[IsOne(n) select 3 else Self(n-1)+NthPrime(n-1): n in [1..50]]; // Bruno Berselli, Jul 30 2013

Mathematica

Accumulate[Join[{3}, Prime[Range[60]]]]

Formula

a(n) = A036439(n) + 1 = A014284(n) + 2 = A007504(n-1) + 3 (in this case, n>1).