Properties of the Number -2380

Three Hundred Eighty

Basics

Value: -2381 → -2380 → -2379

Parity: even

Prime: No

Previous Prime:

Next Prime: 1

Digit Sum: 13

Digital Root: 4

Palindrome: No

Factorization: 2 ² × 5 × 7 × 17

Divisors: 1, 2, 4, 5, 7, 10, 14, 17, 20, 28

Polygonal

Triangular: No

Square: No

Pentagonal: Yes

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: -100101001100

Octal: -4514

Duodecimal: -1464

Hexadecimal: -94c

Square: 5664400

Square Root: 48.78524367060187

Classification

Fibonacci: No

Bell Number: No

Factorial Number: No

Regular Number: No

Perfect Number: No

Special

Kaprekar Constant: No

Munchausen Constant: No

Armstrong Number: No

Kaprekar Number: No

Catalan Number: No

Vampire Number: No

Taxicab Number: No

Super Prime: No

Friedman Number: No

Fermat Number: No

Cullen Number: No

OEIS Sequences

T(n, k) = [x^k] (-1)ⁿ*∑_k=0..n E2(n, n-k)*(1+x)^n-k where E2(n, k) are the second-order Eulerian numbers. Triangle read by rows, T(n, k) for n >= 1 and 0 <= k <= n. A111999

Expansion of Product (1 - x^k)¹⁰ in powers of x. A10818

G.f.: A(x) = ∑_n=-oo..+oo (x - xⁿ)ⁿ. A290003

a(n) = -∑_i=1..n ∑_j=1..n ∑_k=1..n (-1)^i+j+k * (i+j+k)!/(3!*i!*j!*k!). A307350

a(n)=5a(n-1)-11a(n-2)+13a(n-3)-9a(n-4)+3a(n-5)-a(n-6). A140342

a(n) = ceiling( 4ⁿ/20 - (n² + 1)*2^n-1 ). A188162

Expansion of ∑_k>0 x^4·k/(1+x^k)⁵. A363618

a(n) = A023194 - A062700(n). Negative values of A071166(m) = m-A006530(A000203(m)) differences. In these cases m is square number from A023194. A71167

Riordan array (1/((1-2x)(1-x)²), -x/(1-x)²). A135552

Triangle, T(n, k) = (1/2)*(n+2)! * [x^k]( p(x, n) ), where p(x,0) = 1, p(x,1) = -x, P(x, n) = (1/(n+1))*( (2·n-x)*P(x, n-1) - n·P(x, n-2) ), read by rows. A136532