A142074 Prime number superposition a(n) = 10*A008578(2n-1) + A008578(2n).

12, 35, 81, 147, 213, 321, 411, 477, 589, 677, 783, 873, 987, 1113, 1179, 1257, 1447, 1539, 1667, 1797, 1909, 2001, 2127, 2201, 2457, 2523, 2631, 2767, 2899, 2987, 3093, 3237, 3423, 3501, 3717, 3843, 3957, 4109, 4219, 4371

Offset: 1

Author

Paul Curtz, Sep 15 2008

Keywords

• nonn
• easy
• less

Comments

The two factors 10 and 1 of this linear combination could be replaced by any other pair of integers.

Programs

Maple

A008578 := proc(n) if n = 1 then 1; else ithprime(n-1) ; end if; end proc:
A142074 := proc(n) 10*A008578(2*n-1)+A008578(2*n) ; end proc: # R. J. Mathar, Jul 07 2011

Mathematica

Join[{12},10#[[1]]+#[[2]]&/@Partition[Prime[Range[2,80]],2]] (* Harvey P. Dale, Aug 11 2017 *)

Formula

a(n) = 10*prime(2n-2)+prime(2n-1), n>1.