A061788 a(n) = Sum_{k=1..n} (2k)^(2k).

4, 260, 46916, 16824132, 10016824132, 8926117272388, 11120932942830404, 18457865006652382020, 39364865940303189957444, 104896964865940303189957444, 341532774329085497699836681028, 1334077309624613209946781309524804, 6157453657516781924006621069709728580

Offset: 1

Author

Amarnath Murthy, May 25 2001

Keywords

• nonn
• easy

Examples

			a(3) = 2^2 + 4^4 + 6^6 = 46916.
		

Links

• Harry J. Smith, Table of n, a(n) for n = 1..100

Programs

GAP

List([1..13],n->Sum([1..n],k->(2*k)^(2*k))); # Muniru A Asiru, Jul 01 2018

Mathematica

Accumulate[#^#&/@(2Range[20])] (* Harvey P. Dale, May 04 2013 *)

PARI

{ a=n=0; forstep (p=2, 200, 2, write("b061788.txt", n++, " ", a+=p^p) ) } \\ Harry J. Smith, Jul 28 2009

Extensions

More terms from Jason Earls, May 26 2001

More terms from Harvey P. Dale, May 04 2013