A137345 a(n) = binomial( n(n+1)/2, n) mod n.

0, 1, 2, 2, 3, 0, 4, 4, 5, 0, 6, 7, 7, 0, 9, 8, 9, 0, 10, 0, 3, 0, 12, 6, 13, 13, 5, 0, 15, 4, 16, 16, 24, 0, 20, 12, 19, 0, 4, 38, 21, 0, 22, 22, 30, 0, 24, 12, 25, 25, 18, 0, 27, 0, 45, 51, 51, 0, 30, 0, 31, 0, 35, 32, 35, 0, 34, 0, 33, 10, 36, 0, 37, 0, 39, 57, 14, 0, 40, 12, 5, 0, 42, 40

Offset: 1

Author

Paolo P. Lava and Giorgio Balzarotti, Apr 08 2008, Apr 14 2008

Keywords

• easy
• nonn

Crossrefs

Cf. A139125.

Programs

Maple

P:=proc(n) local a,b,i; a:=0; for i from 1 by 1 to n do a:=a+i; b:=(binomial(a,i) mod i); print(b); od; end: P(101);

Formula

a(n) = A014068(n) mod n. - R. J. Mathar, Apr 09 2008