A065343 Smallest k such that usigma(n+k) = usigma(k).

14, 18, 85, 51, 6, 34, 10, 15, 14, 21, 18, 35, 36, 33, 26, 30, 72, 65, 34, 42, 30, 57, 231, 70, 30, 30, 42, 66, 54, 106, 58, 60, 116, 93, 42, 105, 140, 249, 60, 84, 30, 134, 82, 114, 70, 174, 220, 140, 66, 105, 98, 147, 66, 178, 90, 105, 78, 298, 154, 291, 118, 90, 90

Offset

1,1

Links

Harry J. Smith, Table of n, a(n) for n = 1..1000

Prog

(PARI) usigma(n)= { local(f, s=1); f=factor(n); for(i=1, matsize(f)[1], s*=1 + f[i, 1]^f[i, 2]); return(s) }
a(n) = { my(k=1); while (usigma(n + k) != usigma(k), k++); k } \\ Harry J. Smith, Oct 16 2009

Crossrefs

Cf. A034448.

Sequence in context: A154864 A328239 A186120 * A222576 A165228 A205866

Adjacent sequences: A065340 A065341 A065342 * A065344 A065345 A065346

Keyword

nonn

Author

Jason Earls, Dec 02 2001

Status

approved