A136739 (0, 1, 2, 3, 2^2, 5, 2*3, 7, 2^3, 3^2, 2*5, 11, 2^2*3, 13, ...) transform in (0*(1+2), 3*(2+2), 5*(2+3), 7*(2+3), 3*(2+2), 5*(11+2), 2*(3+13), ...).

0, 12, 25, 35, 12, 65, 32, 20, 30, 85, 42, 16, 91, 115, 21, 32, 12, 217, 108, 16, 209, 45, 10, 777, 45, 138, 20, 172, 55, 125, 282, 27, 14, 57, 132, 12, 65, 30, 589, 236, 198, 68, 18, 108, 28, 268, 442, 24, 355, 225, 80, 20, 52, 55, 1053, 32, 172, 332, 36, 765, 93, 300

Offset

1,2

Links

Michael De Vlieger, Table of n, a(n) for n = 1..10000

Example

a(1) = 0*(1+2)  = 0;
a(2) = 3*(2+2)  = 12;
a(3) = 5*(2+3)  = 25;
a(4) = 7*(2+3)  = 35;
a(5) = 3*(2+2)  = 12;
a(6) = 5*(11+2) = 65;
a(7) = 2*(3+13) = 32;
a(8) = 2*(7+3)  = 20; etc.

Mathematica

#1 (#2 + #3) & @@ # & /@ Partition[#, 3, 3] &@ Flatten[{0}~Join~Array[Map[If[Last@ # == 1, First@ #, #] &, FactorInteger@ #] &, 89]] (* Michael De Vlieger, Jan 01 2017 *)

Crossrefs

Cf. A141269, A141270.

Sequence in context: A033165 A224676 A239147 * A186620 A042851 A280324

Adjacent sequences: A136736 A136737 A136738 * A136740 A136741 A136742

Keyword

nonn

Author

Juri-Stepan Gerasimov, Oct 31 2008

Extensions

Entries checked by R. J. Mathar, Apr 25 2010

Status

approved