A237607 Numbers divisible by a square and which have the same property if any number of rightmost digits is deleted.

4, 8, 9, 40, 44, 45, 48, 49, 80, 81, 84, 88, 90, 92, 96, 98, 99, 400, 404, 405, 408, 440, 441, 444, 448, 450, 452, 456, 459, 480, 484, 486, 488, 490, 492, 495, 496, 800, 801, 804, 808, 810, 812, 816, 819, 840, 841, 844, 845, 846, 847, 848, 880, 882, 884, 888

Offset

1,1

Comments

This regards the interplay between an endomorphism E on the set N and a number property P. In this case, E(n)=floor(n/10) for n >=10 and E(n)=n otherwise, and the property P is "moebius(n)=0". The goal is to find the numbers whose consecutive images under E all have the property P.

Links

Stanislav Sykora, Table of n, a(n) for n = 1..20000

Stanislav Sykora, PARI/GP scripts for genetic threads

Prog

(PARI) See the link (use GT_DivMod0 with "IsMoebiusZero" for the "property" argument).

Crossrefs

Subsequence of A013929.

Sequence in context: A162752 A076966 A360758 * A035132 A077572 A385401

Adjacent sequences: A237604 A237605 A237606 * A237608 A237609 A237610

Keyword

nonn,base

Author

Stanislav Sykora, Feb 15 2014

Status

approved