265

Previous  ... Next

Number

$265$ (two hundred and sixty-five) is:

$5 \times 53$

The $6$th subfactorial after $0$, $1$, $2$, $9$, $44$:
$265 = \, !6 = 6! \paren {1 - \dfrac 1 {1!} + \dfrac 1 {2!} - \dfrac 1 {3!} + \dfrac 1 {4!} - \dfrac 1 {5!} + \dfrac 1 {6!} }$

The $10$th Smith number after $4$, $22$, $27$, $58$, $85$, $94$, $121$, $166$, $202$:
$2 + 6 + 5 = 5 + 5 + 3 = 13$

The $14$th number after $1$, $3$, $22$, $66$, $70$, $81$, $94$, $115$, $119$, $170$, $210$, $214$, $217$ whose divisor sum is square:
$\map {\sigma_1} {265} = 324 = 18^2$

The $14$th positive integer after $50$, $65$, $85$, $125$, $130$, $145$, $170$, $185$, $200$, $205$, $221$, $250$, $260$ which can be expressed as the sum of two square numbers in two or more different ways:
$265 = 16^2 + 3^2 = 12^2 + 11^2$

The $17$th positive integer $n$ after $0$, $1$, $5$, $25$, $29$, $41$, $49$, $61$, $65$, $85$, $89$, $101$, $125$, $145$, $149$, $245$ such that the Fibonacci number $F_n$ ends in $n$

Also see

No further terms of this sequence are documented on $\mathsf{Pr} \infty \mathsf{fWiki}$.