179101

Appears in sequences

• Concatenation of triangular number k and its 10's complement is prime.at n=31A108970
• Triangular numbers whose digit reversal is a brilliant number (A078972).at n=13A115678
• Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 0100-1110-0111-0010 pattern in any orientation.at n=13A146916
• Number of -1..1 arrays x(0..n-1) of n elements with zero sum and no two consecutive declines, no adjacent equal elements, and no element more than one greater than the previous (random base sawtooth pattern).at n=33A200174
• Sequence of distinct least positive triangular numbers such that the arithmetic mean of the first n terms is also a triangular number. Initial term is 1.at n=13A236416