login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A073738 Sum of every other prime <= n-th prime down to 2 or 1; equals the partial sums of A036467 (in which sums of two consecutive terms form the primes). 0
1, 2, 4, 7, 11, 18, 24, 35, 43, 58, 72, 89, 109, 130, 152, 177, 205, 236, 266, 303, 337, 376, 416, 459, 505, 556, 606, 659, 713, 768, 826, 895, 957, 1032, 1096, 1181, 1247, 1338, 1410, 1505, 1583, 1684, 1764, 1875, 1957, 2072, 2156, 2283, 2379, 2510, 2608 (list; graph; refs; listen; history; internal format)
OFFSET

0,2

FORMULA

a(n) = Sum_{m<=n, m=n (mod 2)} p_m, where p_m is the m-th prime; that is, a(2n+k) = p_(2n+k) +p_(2(n-1)+k) +p_(2(n-2)+k) +... +p_k, for 0<=k<2, where a(0)=1 and the 0-th prime is taken to be 1.

EXAMPLE

a(10) = p_10 +p_8 +p_6 +p_4 +p_2 +p_0 = 29 +19 +13 +7 +3 +1 = 72.

MATHEMATICA

nn=60; Join[{1}, Sort[Join[Accumulate[Prime[Range[1, nn+1, 2]]], 1+#&/@ Accumulate[Prime[Range[2, nn, 2]]]]]] (* From Harvey P. Dale, May 04 2011 *)

CROSSREFS

Cf. A036467, A073736.

Sequence in context: A023427 A202847 A129929 * A137631 A003403 A034412

Adjacent sequences:  A073735 A073736 A073737 * A073739 A073740 A073741

KEYWORD

easy,nice,nonn

AUTHOR

Paul D. Hanna (pauldhanna(AT)juno.com), Aug 07 2002

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 15 08:20 EST 2012. Contains 205729 sequences.