121771

Appears in sequences

• a(n) = greatest residue of S(n,m) mod C(n-1,m-1), for m = 1,2,...,n; S(n,m) are Stirling numbers of second kind.at n=20A024424
• Heptagonal triangular numbers.at n=2A046194
• Heptagonal hexagonal numbers.at n=1A048903
• Numbers that are n-gons for three or more n's, where n=3,4,5,...,16.at n=14A062712
• Triangular numbers whose sum of squared digits is also triangular.at n=28A094890
• Expansion of 1/((x-1)*(x+1)*(x^2+x+1)*(x^2+x-1)*(x^2-x+1)*(x^2+1)*(x^4-x^2+1)).at n=25A109609
• Triangular numbers composed of digits {1,2,7}.at n=6A119105
• Numbers k such that sigma(k)/phi(k) = 25/16.at n=3A164648
• Triangular numbers which are sums of three consecutive primes.at n=13A167788
• Triangle T(n,k) read by rows of the smallest n-gonal number greater than 1 that is also k-gonal, or 0 if none exists, for 3 <= k <= n.at n=13A189216
• Q-residue of the triangle A094727, where Q=Pascal's triangle. (See Comments.)at n=7A193659
• Triangular numbers composed of only digits with line segments or both line segments and curves {1, 2, 4, 5, 7}.at n=25A247021
• Decimal representation of the x-axis, from the left edge to the origin, of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 654", based on the 5-celled von Neumann neighborhood.at n=16A283587
• a(n) = (n-1)*(n-2)*(n^2+9*n+12)/24.at n=40A323847
• Least nonnegative number greater than the previous number which is simultaneously an n-gonal and (n+1)-gonal number.at n=6A342300
• Heptagonal numbers which are products of four distinct primes.at n=15A351867
• 4-brilliant numbers with distinct prime factors.at n=22A376864
• Numbers that are both k-gonal and (k+1)-gonal for some k >= 3.at n=6A378245