148 (number)

← 147 148 149 →
← 140 141 142 143 144 145 146 147 148 149 → List of numbers Integers ← 0 100 200 300 400 500 600 700 800 900 →
Cardinal	one hundred forty-eight
Ordinal	148th (one hundred forty-eighth)
Factorization	22 × 37
Divisors	1, 2, 4, 37, 74, 148
Greek numeral	ΡΜΗ´
Roman numeral	CXLVIII, cxlviii
Binary	100101002
Ternary	121113
Senary	4046
Octal	2248
Duodecimal	10412
Hexadecimal	9416

148 (one hundred [and] forty-eight) is the natural number following 147 and before 149.

In mathematics

148 is the second number to be both a heptagonal number and a centered heptagonal number (the first is 1). ^[1] It is the twelfth member of the Mian–Chowla sequence, the lexicographically smallest sequence of distinct positive integers with distinct pairwise sums. ^[2]

There are 148 perfect graphs with six vertices, ^[3] and 148 ways of partitioning four people into subsets, ordering the subsets, and selecting a leader for each subset. ^[4]

In other fields

Dunbar's number is a theoretical cognitive limit to the number of people with whom one can maintain stable interpersonal relationships. Dunbar predicted a "mean group size" of 148, ^[5] but this is commonly rounded to 150.

References

1. Sloane, N. J. A. (ed.). "SequenceA128919(Numbers simultaneously heptagonal and centered heptagonal)". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation.
2. Sloane, N. J. A. (ed.). "SequenceA005282(Mian-Chowla sequence)". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation.
3. Sloane, N. J. A. (ed.). "SequenceA052431(Number of perfect simple undirected graphs on n nodes)". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation.
4. Sloane, N. J. A. (ed.). "SequenceA006153(E.g.f.: 1/(1-x*exp(x)))". The On-Line Encyclopedia of Integer Sequences . OEIS Foundation.
5. Dunbar, R. I. M. (1997). "Groups, Gossip, and the Evolution of Language". In Schmitt, Alain; Atzwanger, Klaus; Grammer, Karl; Schäfer, Katrin (eds.). New Aspects of Human Ethology. Kluwer Academic Publishers. pp. 77–89. doi:10.1007/978-0-585-34289-4_5. ISBN   978-0-306-45695-4.