OFFSET
1,2
COMMENTS
LINKS
Tilman Piesk, First 113 rows of the triangle, flattened
FORMULA
T(m,n) = ( 2^(n+1)^m -1 ) * ( 2^n -1 ) / ( 2^(n+1) -1 ).
EXAMPLE
Array starts: Binary:
n 1 2 3 4 5
m
1 1 3 7 15 31 1 11 111
2 5 27 119 495 2015 101 11011 1110111
3 21 219 1911 15855 128991 10101 11011011 11101110111
4 85 1755 30583 507375 8255455
5 341 14043 489335 16236015 528349151
PROG
(PHP)
<?php function A249544($m, $n) {
// a b c
// ( 2^(n+1)^m -1 ) * ( 2^n -1 ) / ( 2^(n+1) -1 )
$a = gmp_sub( gmp_pow( gmp_pow(2, $n+1), $m ), 1 );
$b = gmp_sub( gmp_pow(2, $n), 1 );
$c = gmp_sub( gmp_pow(2, $n+1), 1 );
$return = gmp_div_q( gmp_mul($a, $b), $c );
return gmp_strval($return);
}
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Tilman Piesk, Oct 31 2014
STATUS
approved