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A086075
Number of 4's in decimal expansion of triangular number n(n+1)/2.
10
0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 1, 0, 0, 1, 0, 0, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1
OFFSET
0,95
MATHEMATICA
DigitCount[Accumulate[Range[0, 100]], 10, 4] (* Paolo Xausa, May 05 2024 *)
CROSSREFS
Cf. 0's A086071, 1's A086072, 2's A086073, 3's A086074, 5's A086076, 6's A086077, 7's A086078, 8's A086079, 9's A086080.
Sequence in context: A055641 A218245 A352516 * A316865 A325616 A056978
KEYWORD
base,nonn
AUTHOR
Jason Earls, Jul 08 2003
STATUS
approved