238 (two hundred [and] thirty-eight) is the natural number following 237 and preceding 239.
← 237 238 239 → | |
---|---|
Cardinal | two hundred thirty-eight |
Ordinal | 238th (two hundred thirty-eighth) |
Factorization | 2 × 7 × 17 |
Prime | no |
Greek numeral | ΣΛΗ´ |
Roman numeral | CCXXXVIII |
Binary | 111011102 |
Ternary | 222113 |
Octal | 3568 |
Duodecimal | 17A12 |
Hexadecimal | EE16 |
238 is an untouchable number.[1] There are 238 2-vertex-connected graphs on five labeled vertices,[2] and 238 order-5 polydiamonds (polyiamonds that can partitioned into 5 diamonds).[3] Out of the 720 permutations of six elements, exactly 238 of them have a unique longest increasing subsequence.[4]
References
- ^ Sloane, N. J. A. (ed.). "Sequence A005114 (Untouchable numbers: impossible values for sum of aliquot parts of n)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ^ Sloane, N. J. A. (ed.). "Sequence A013922 (Number of labeled connected graphs with n nodes and 0 cutpoints (blocks or nonseparable graphs))". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ^ Sloane, N. J. A. (ed.). "Sequence A056844 (Number of polydiamonds: polyominoes made from n diamonds)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ^ Sloane, N. J. A. (ed.). "Sequence A167995 (Total number of permutations on {1,2,...,n} that have a unique longest increasing subsequence)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.