A086076 Number of 5's in decimal expansion of triangular number n(n+1)/2.

0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 2, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 1, 1, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 1, 2, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 0, 0, 0, 1, 1, 0, 0, 0, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 1

Offset

0,11

Links

Table of n, a(n) for n=0..104.

Mathematica

DigitCount[#, 10, 5]&/@Accumulate[Range[0, 110]] (* Harvey P. Dale, Sep 24 2016 *)

Crossrefs

Cf. 0's A086071, 1's A086072, 2's A086073, 3's A086074, 4's A086075, 6's A086077, 7's A086078, 8's A086079, 9's A086080.

Sequence in context: A351726 A285720 A269175 * A334348 A316717 A328831

Adjacent sequences: A086073 A086074 A086075 * A086077 A086078 A086079

Keyword

base,nonn

Author

Jason Earls, Jul 08 2003

Status

approved