A333503 Differences between consecutive odd abundant numbers.

630, 630, 630, 630, 630, 630, 630, 420, 210, 450, 180, 210, 420, 180, 450, 210, 330, 90, 420, 210, 420, 210, 630, 630, 630, 630, 420, 210, 630, 630, 630, 210, 420, 630, 630, 630, 630, 630, 630, 90, 330, 210, 630, 630, 630, 210, 330, 90, 630, 210, 420, 630, 630

Offset

1,1

Comments

a(n) = A005231(n+1) - A005231(n).

Since 945+1890*k is odd and abundant for all k, 1890 is the maximal term that occurs. The first time it occurs is for a(274)=1890, and the involved odd abundant numbers are 135135 and 137025.

Clearly 2 is the minimal term that can occur. For an example, see comment to A294025.

Links

Jeppe Stig Nielsen, Table of n, a(n) for n = 1..1000

Mathematica

Differences@ Select[Range[947, 3*10^4 + 1, 2], DivisorSigma[1, #] > 2 # &] (* Michael De Vlieger, Mar 25 2020 *)

Prog

(PARI) my(oldn=945); forstep(n=947, 5*10^4, 2, if(sigma(n)>2*n, print1(n-oldn, ", "); oldn=n))

Crossrefs

Cf. A005231, A294025.

Sequence in context: A098261 A256937 A177421 * A173423 A295769 A110904

Adjacent sequences: A333500 A333501 A333502 * A333504 A333505 A333506

Keyword

nonn

Author

Jeppe Stig Nielsen, Mar 24 2020

Status

approved