A061464 Denominator of 1/(1^1) + 1/(2^2) + 1/(3^3) + ... 1/(n^n).

1, 1, 4, 108, 6912, 21600000, 583200000, 480290277600000, 31476303632793600000, 16727798278915463577600000, 52274369621610823680000000000, 14914487726878692033020558868480000000000

Offset: 0

Author

Amarnath Murthy, May 04 2001

Keywords

• nonn
• frac
• easy

Examples

			1, 5/4, 139/108, 8923/6912,...
		

Crossrefs

Cf. A061463, A073009.

Programs

Maple

summ := 0; for n from 1 to 15 do printf("%d ", denom(summ)); if (1 = 1) then summ := summ + 1/n^n: end if; od;

Mathematica

Join[{1},Denominator/@Table[Sum[1/i^i,{i,n}],{n,12}]] (* Harvey P. Dale, Jul 03 2011 *)

PARI

a(n) = denominator(sum(k=1, n, 1/(k^k))) \\ Thomas Scheuerle, Feb 26 2025

Formula

A061463(n)/a(n) = Integral_{x=0..1} Gamma(n, -x*log(x))/(x^x*Gamma(n)) dx. - Thomas Scheuerle, Feb 26 2025

Extensions

More terms from Winston C. Yang (winston(AT)cs.wisc.edu), May 19 2001

a(12) from Harvey P. Dale, Jul 03 2011