A332575 Least start of a run of exactly n consecutive numbers that are norm-abundant in Gaussian integers (A332570).

2, 9, 4, 12, 24, 185, 114, 1649, 692, 4977, 1412, 416345, 22624, 72233, 199892, 25262152, 1351880, 130824185, 16305324, 1688906313, 9412730, 10393378914, 721753400

Offset

1,1

Links

Table of n, a(n) for n=1..23.

Example

a(2) = 9 since 9 and 10 are the least pair of 2 consecutive numbers that are norm-abundant in Gaussian integers, and 8 and 11 are not norm-abundant.

Mathematica

normAbQ[z_] := Abs[DivisorSigma[1, z, GaussianIntegers -> True]]^2 > 2*Abs[z]^2; n = 1; count = 0; max = 15; seq = Table[0, {max}]; While[count < max, n1 = n; If[normAbQ[n], While[normAbQ[++n1]]; d = n1 - n; If[d <= max && seq[[d]] == 0, count++; seq[[d]] = n]]; n = n1 + 1]; seq

Crossrefs

Cf. A005101, A096399, A096536, A103228, A103229, A103230, A332570.

Sequence in context: A021343 A200703 A342663 * A080803 A370500 A339316

Adjacent sequences: A332572 A332573 A332574 * A332576 A332577 A332578

Keyword

nonn,more

Author

Amiram Eldar, Feb 16 2020

Status

approved