A072518 Index of smallest triangular number beginning with the n-th triangular number other than itself.

4, 8, 11, 14, 17, 20, 75, 85, 95, 105, 36, 39, 135, 145, 155, 165, 553, 58, 616, 648, 680, 711, 743, 77, 806, 838, 869, 901, 933, 96, 996, 1028, 1059, 1091, 1122, 1154, 1186, 1217, 1249, 4050, 1312, 1344, 1375, 1407, 4550, 1470, 1502, 4850, 1565, 5050

Offset

1,1

Links

Table of n, a(n) for n=1..50.

Example

a(7) = 75 as the 75th triangular number 2850 > 28 is the smallest triangular number beginning with 28 which is the seventh triangular number.

Crossrefs

Cf. A072517.

Sequence in context: A327136 A311032 A311033 * A113553 A342279 A248228

Adjacent sequences: A072515 A072516 A072517 * A072519 A072520 A072521

Keyword

base,nonn

Author

Amarnath Murthy, Jul 31 2002

Extensions

Corrected and extended by Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Apr 25 2003

Status

approved