A332314 Numbers k such that k, k + 1, k + 2 and k + 3 have the same number of divisors in Gaussian integers.

263449773, 334047725, 760228973, 862305773, 1965540624, 2136055725, 2362380525, 2477365422, 2515570575, 2613782223, 2939626925, 3181603023, 3814526223, 3987335022, 4610697039, 4771214574, 4981539822, 5018728272, 5035157775, 5186567824, 6189727725, 6329159823, 6569396973

Offset

1,1

Links

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

Example

263449773 is a term since 263449773, 263449774, 263449775 and 263449776 each have 72 divisors in Gaussian integers.

Mathematica

gaussNumDiv[n_] := DivisorSigma[0, n, GaussianIntegers -> True]; m = 4; s = gaussNumDiv /@ Range[m]; seq = {}; n = m + 1; While[Length[seq] < 10, If[Length @ Union[s] == 1, AppendTo[seq, n - m + 1]]; n++; s = Join[Rest[s], {gaussNumDiv[n]}]]; seq

Crossrefs

Cf. A006601, A062327, A332312, A332313.

Sequence in context: A226448 A250433 A329464 * A125576 A233501 A295477

Adjacent sequences: A332311 A332312 A332313 * A332315 A332316 A332317

Keyword

nonn

Author

Amiram Eldar, Feb 09 2020

Status

approved