login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A050227
Triangle of number of n-tosses having a run of r or more heads for a fair coin with r=1 to n across and n=1, 2, ... down.
3
1, 3, 1, 7, 3, 1, 15, 8, 3, 1, 31, 19, 8, 3, 1, 63, 43, 20, 8, 3, 1, 127, 94, 47, 20, 8, 3, 1, 255, 201, 107, 48, 20, 8, 3, 1, 511, 423, 238, 111, 48, 20, 8, 3, 1, 1023, 880, 520, 251, 112, 48, 20, 8, 3, 1, 2047, 1815, 1121, 558, 255, 112, 48, 20, 8, 3, 1, 4095, 3719
OFFSET
1,2
REFERENCES
W. Feller, An Introduction to Probability Theory and Its Applications, Vol. 1, 2nd ed. New York: Wiley, p. 300, 1968.
LINKS
Eric Weisstein's World of Mathematics, Coin Tossing.
Eric Weisstein's World of Mathematics, Run.
EXAMPLE
Triangle begins:
1;
3, 1;
7, 3, 1;
15, 8, 3, 1;
31, 19, 8, 3, 1
...
MATHEMATICA
Clear[fib]; fib[n_, n_] = 1; fib[n_, k_] /; k > n = 0; fib[n_, k_] := fib[n, k] = If[k == 1, 1, Sum[fib[m, k], {m, n - k , n - 1}]]; Table[ 2^n - fib[n + k + 1 , k], {n, 1, 12}, {k, 1, n}] // Flatten (* Jean-François Alcover, Jan 15 2013 *)
CROSSREFS
KEYWORD
nonn,nice,tabl
STATUS
approved