A220343 The number of decades below 10^n whose semiprime pattern is the same as semiprime pattern in the previous decade.

0, 0, 7, 114, 1794, 24605

Offset

1,3

Links

Table of n, a(n) for n=1..6.

Example

a(3) = 7 because the 7 values less than 10^3 are 104, 389, 435, 438, 529, 658, 884.

Crossrefs

Cf. A220063.

Sequence in context: A086788 A199672 A240288 * A183403 A127877 A082487

Adjacent sequences: A220340 A220341 A220342 * A220344 A220345 A220346

Keyword

nonn,base

Author

Robert G. Wilson v, Jonathan Vos Post, Dec 11 2012

Status

approved