A129133 Numbers whose trajectory under the Esucarys map ends at the fixed point 247.

247, 1247, 1484, 2473, 4859, 5087, 5738, 7318, 7484, 9563, 9682, 9694, 9938, 11247, 12189, 12473, 14840, 14842, 15209, 15610, 16274, 16563, 16750, 16798, 17609, 19168, 20019, 21885, 24733, 26251, 27123, 27125, 29156, 30076, 30524, 32614, 43899, 44274, 45098, 45787, 48593, 49682, 49694, 49697

Offset

1,1

Comments

Old title was: "(c,n) is the n-th number for which the Esucarys sequence starting from it reaches 247 and from there keeps indefinitely this value."

The name "Esucarys" is a reversal of "Syracuse", with the generating rule being that for the Syracuse sequence followed by a reversal.

247 is the only known fixed point of the Esucarys sequence. - Charlie Neder, Jan 12 2019

Links

Charlie Neder, Table of n, a(n) for n = 1..560

Example

For c < 1247 no sequence starting from c except 247 itself reaches 247.
S(1247)=2473, then E(1247) = 3742.
S(3742)=7420, then E(3742) = 247, then (c,1) = 247 and (c,2) = 1247.

Crossrefs

Cf. A006577, A129121.

Sequence in context: A127349 A051153 A166399 * A251265 A001243 A048901

Adjacent sequences: A129130 A129131 A129132 * A129134 A129135 A129136

Keyword

easy,nonn,base,uned

Author

Philippe LALLOUET (philip.lallouet(AT)wanadoo.fr), May 25 2007

Extensions

Extended, missing a(5) and a(6) added, and name changed by Charlie Neder, Jan 12 2019

Status

approved