23453

Appears in sequences

• Discriminants of real quadratic fields with class number 1 and related continued fraction period length of 20.at n=31A050969
• Composite and every divisor (except 1) contains the digit 4.at n=18A062670
• Integers are written in the form abcd...n where "a" means "At position a in this integer there is a digit b"; "b" means: "at position b there is a digit c"; "c" means: "at position c there is a digit d"; ... and "n" means nothing. No repetitions are allowed (like in the integer 111).at n=40A105958
• a(n) = (9 + 14*n + 12*n^2 + 4*n^3)/3.at n=25A166911
• a(n) = T(10,n), array T given by A048505.at n=7A195856
• Number of (n+4)X6 0..2 matrices with each 5X5 subblock idempotent.at n=4A224619
• Number of (n+4) X 9 0..2 matrices with each 5 X 5 subblock idempotent.at n=1A224622
• T(n,k)=Number of (n+4)X(k+4) 0..2 matrices with each 5X5 subblock idempotent.at n=16A224625
• T(n,k)=Number of (n+4)X(k+4) 0..2 matrices with each 5X5 subblock idempotent.at n=19A224625
• The 180-degree spoke (or ray) of a hexagonal spiral of Ulam.at n=44A244806
• Number of 1 X n 0..2 arrays with every repeated value in every row unequal to the previous repeated value, and in every column equal to the previous repeated value, and new values introduced in row-major sequential order.at n=11A267912
• Number of unlabeled connected loopless multigraphs with n nodes of degree 4 or less and with at most double edges.at n=8A289158