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A061380 Triangular numbers with product of digits also a triangular number. 0
0, 1, 3, 6, 10, 66, 105, 120, 153, 190, 210, 231, 300, 351, 406, 465, 630, 703, 741, 780, 820, 903, 990, 1035, 1081, 1326, 1540, 1770, 1830, 2016, 2080, 2556, 2701, 2850, 3003, 3081, 3160, 3240, 3403, 3570, 4005, 4095, 4560, 4950, 5050, 5460, 5671, 6105 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..47.

EXAMPLE

153 is a triangular number and the product of digits 15 is also a triangular number.

PROG

(MAGMA) [t: n in [0..110] | IsSquare(8*p+1) where p is &*Intseq(t) where t is (n*(n+1) div 2)];  // Bruno Berselli, Jun 30 2011

CROSSREFS

Sequence in context: A068071 A067269 A071299 * A125567 A254957 A124266

Adjacent sequences:  A061377 A061378 A061379 * A061381 A061382 A061383

KEYWORD

nonn,base,easy

AUTHOR

Amarnath Murthy, May 02 2001

EXTENSIONS

More terms from Erich Friedman, May 08 2001

STATUS

approved

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Last modified April 19 07:11 EDT 2019. Contains 322237 sequences. (Running on oeis4.)