238 (number)

238 (two hundred [and] thirty eight) is the natural number following 237 and preceding 239.

← 237 238 239 →
← 200 210 220 230 240 250 260 270 280 290 → List of numbers — Integers ← 0 100 200 300 400 500 600 700 800 900 →
Cardinal	two hundred thirty-eight
Ordinal	238th (two hundred and thirty-eighth)
Factorization	2 × 7 × 17
Prime	no
Roman numeral	CCXXXVIII
Binary	111011102
Ternary	222113
Quaternary	32324
Quinary	14235
Senary	10346
Octal	3568
Duodecimal	17A12
Hexadecimal	EE16
Vigesimal	BI20
Base 36	6M36

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] Among the 720 permutations of six elements, exactly 238 of them have a unique longest increasing subsequence.^[4]

References

1. "Sloane's A005114 : Untouchable numbers: impossible values for sum of aliquot parts of n", The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
2. "Sloane's 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.
3. "Sloane's A056844 : Number of polydiamonds: polyominoes made from n diamonds", The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
4. "Sloane's 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.