91378

Appears in sequences

• Triangular numbers with sum of digits = 28.at n=27A068132
• a(1) = 7; a(n+1) = smallest triangular number > a(n) formed by adding at least one digit to a(n).at n=4A068621
• Triangular numbers such that both the number formed by the first floor((k+1)/2) digits and the remaining part (if any) are triangular numbers, where k is the number of digits.at n=16A068821
• Triangular number x such that x + reverse of x is a prime.at n=22A072387
• Numbers k > 1 for which floor(b(k)) = floor(b(k-1)), where b(m) = Sum_{j=1..m} (j/(j+2)).at n=20A133470
• Triangular numbers representable as x*y+x+y such that x and y are triangular numbers, x>=y>0.at n=28A259745
• Triangular numbers representable as x*y+x+y such that x and y are triangular numbers, x>=y>1.at n=23A259746
• The first of three consecutive triangular numbers the sum of which is equal to the sum of three consecutive primes.at n=32A298168
• Number of triples (i,j,k) such that i+j+k > 0 with -n <= i,j,k <= n.at n=28A302302
• Number of integer compositions of n with weighted alternating sum 0.at n=24A363626
• Hexagonal numbers that are products of exactly four distinct primes.at n=38A381920