A080524 Triangle read by rows in which the n-th row contains n distinct numbers whose sum is n^n. The numbers are terms of an arithmetic progression with a common difference 1 or 2 respectively accordingly as n is odd or even.

1, 1, 3, 8, 9, 10, 61, 63, 65, 67, 623, 624, 625, 626, 627, 7771, 7773, 7775, 7777, 7779, 7781, 117646, 117647, 117648, 117649, 117650, 117651, 117652, 2097145, 2097147, 2097149, 2097151, 2097153, 2097155, 2097157, 2097159, 43046717, 43046718

Offset

1,3

Links

Table of n, a(n) for n=1..38.

Formula

For 1 <= i <= n, T(n, i) = n^(n-1) + (2i - n - 1)/2 if n odd; n^(n-1) + (2i-n-1) if n even. - C. Ronaldo (aga_new_ac(AT)hotmail.com), Jan 18 2005

Example

Triangle begins
    1;
    1,   3;
    8,   9,  10;
   61,  63,  65,  67;
  623, 624, 625, 626, 627;

Maple

l:=[]: for n from 1 to 9 do d:=2-(n mod 2): a:=n^(n-1)-d*(n-1)/2: l:=[op(l), seq(a+d*(i-1), i=1..n)] od: op(l); T:=proc(n, i) local d: d:=2-(n mod 2): RETURN(n^(n-1)+d*(2*i-n-1)/2): end: seq(seq(T(n, i), i=1..n), n=1..9); # C. Ronaldo, Jan 18 2005

Crossrefs

Cf. A080525, A080526.

Sequence in context: A211223 A350776 A247544 * A024550 A173179 A225555

Adjacent sequences: A080521 A080522 A080523 * A080525 A080526 A080527

Keyword

nonn,tabl

Author

Amarnath Murthy, Mar 21 2003

Extensions

More terms from C. Ronaldo (aga_new_ac(AT)hotmail.com), Jan 18 2005

Status

approved