A157756 Integers n such that by splitting their digits in two equal parts, the difference between the square of the first part and the second part eventually reaches 0 by iterating the process. If length is odd, split (length+1)/2, (length-1)/2.

0, 11, 24, 39, 45, 51, 74, 97, 103, 150, 151, 155, 220, 224, 225, 229, 230, 234, 240, 290, 291, 330, 349, 363, 373, 383, 420, 424, 425, 429, 445, 458, 460, 464, 470, 474, 475, 479, 480, 484, 491, 503, 504, 508, 515, 525, 529, 557, 564, 576, 577, 581, 591

Offset

1,2

Comments

Example 3480 belongs to the sequence, because 34^2 - 80 = 1076 --> 10^2 - 76 = 24 --> 2^2 - 4 = 0.

Links

Table of n, a(n) for n=1..53.

Jean-Marc Falcoz, Illustration of directed graph, zoomable picture (up to 1000).

Jean-Marc Falcoz, List of terms up to 11000.

Crossrefs

Sequence in context: A213991 A269100 A213062 * A061043 A349487 A098603

Adjacent sequences: A157753 A157754 A157755 * A157757 A157758 A157759

Keyword

base,easy,nonn

Author

Jean-Marc Falcoz, Mar 06 2009

Status

approved