A068132 - OEIS

A068132

Triangular numbers with sum of digits = 28.

5995, 14878, 17578, 24976, 29890, 32896, 36856, 37675, 42778, 47278, 52975, 53956, 54946, 55945, 56953, 57970, 67528, 68635, 69751, 70876, 75466, 76636, 77815, 83845, 85078, 87571, 88831, 91378, 92665, 93961, 95266, 96580, 97903

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OFFSET

1,1

COMMENTS

The sequence is unbounded, as the (10^k + 9)-th triangular number for k>1 is a term.

The sum of the digits of triangular numbers in most cases is a triangular number.

Conjecture: For every triangular number T there exist infinitely many triangular numbers with sum of digits = T.

LINKS

Table of n, a(n) for n=1..33.

MATHEMATICA

Select[Accumulate[Range[500]], Total[IntegerDigits[#]]==28&] (* Harvey P. Dale, Aug 30 2015 *)

CROSSREFS

Subsequence of A000217.

Cf. A068127, A068128, A068129, A068130, A068131.

Sequence in context: A055108 A046903 A171351 * A250514 A343432 A115429

Adjacent sequences: A068129 A068130 A068131 * A068133 A068134 A068135

KEYWORD

base,easy,nonn

AUTHOR

Amarnath Murthy, Feb 21 2002

EXTENSIONS

More terms from Sascha Kurz, Mar 06 2002

Offset changed by Andrew Howroyd, Sep 19 2024

STATUS

approved