A059399 Triangular hopscotch.

1, 3, 2, 6, 4, 5, 10, 7, 9, 8, 15, 11, 14, 12, 13, 21, 16, 20, 17, 19, 18, 28, 22, 27, 23, 26, 24, 25, 36, 29, 35, 30, 34, 31, 33, 32, 45, 37, 44, 38, 43, 39, 42, 40, 41, 55, 46, 54, 47, 53, 48, 52, 49, 51, 50, 66, 56, 65, 57, 64, 58, 63, 59, 62, 60, 61

Offset

1,2

Links

Harry J. Smith, Table of n, a(n) for n = 1..10011

Formula

Write down triangle with rows 1; 2, 3; 4, 5, 6; 7, 8, 9, 10; ...; read rows alternately from right and left ends.

Prog

(PARI) { n=0; for (i = 1, 141, d=i; s=1; for (j=1, i, if (j==1, a=(i^2 + i)/2, a+=s*d); write("b059399.txt", n++, " ", a); d--; s=-s; ); ) } \\ Harry J. Smith, Jun 26 2009

Crossrefs

Sequence in context: A352200 A066182 A195114 * A194984 A194988 A195074

Adjacent sequences: A059396 A059397 A059398 * A059400 A059401 A059402

Keyword

nonn,easy

Author

Robert G. Wilson v, Jan 29 2001

Status

approved