A073060 Multiplication table for 1 and odd primes, read by antidiagonals.

1, 3, 3, 5, 9, 5, 7, 15, 15, 7, 11, 21, 25, 21, 11, 13, 33, 35, 35, 33, 13, 17, 39, 55, 49, 55, 39, 17, 19, 51, 65, 77, 77, 65, 51, 19, 23, 57, 85, 91, 121, 91, 85, 57, 23, 29, 69, 95, 119, 143, 143, 119, 95, 69, 29, 31, 87, 115, 133, 187, 169, 187, 133, 115, 87, 31, 37, 93, 145

Offset

0,2

Comments

Entries in table are sometimes called semiprimes or biprimes (see A001358).

Links

Table of n, a(n) for n=0..68.

Example

Table begins
1 3 5 7 11 13 ...
3 9 15 21 33 ...
5 15 25 35 ...

Maple

a[1] := 1:for j from 2 to 100 do a[j] := ithprime(j):od:s := 0:for j from 1 to 16 do for i from 1 to j do s := s+1:b[s] := a[j-i+1]*a[i]; od:od:seq(b[q], q=1..s);

Crossrefs

Sequence in context: A293676 A303714 A098353 * A183526 A337562 A087343

Adjacent sequences: A073057 A073058 A073059 * A073061 A073062 A073063

Keyword

nonn,tabl,easy

Author

Stuart M. Ellerstein (ellerstein(AT)aol.com), Aug 16 2002

Extensions

Corrected and extended by Sascha Kurz, Jan 28 2003

Status

approved