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A179653 Triangular numbers (A000217) which are also primes in carryless digital root arithmetic in base 10 (A169911). 0
3, 6, 10, 15, 21, 28, 45, 55, 78, 91, 105, 136, 406, 496, 528, 595, 703, 741, 1035, 1081, 1225 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The complement, triangular numbers (A000217) which are not primes in carryless digital root arithmetic in base 10 (A169911), begins {1, 36, 66, 153, 171, 190, 210, 231, 253, 276, 300, 325, 351, 378, 435, 465, ...}.

LINKS

Table of n, a(n) for n=1..21.

Index entries for sequences related to carryless arithmetic

FORMULA

A000217 INTERSECTION A169911.

EXAMPLE

1, though triangular, is a unit, not a prime, in standard or carryless arithmetic.

36 is triangular, A000217(8), yet not in A169911 since in carryless digital root arithmetic in base 10 we have 3*15 = 36 where both 3 and 15 are primes, and 3*18=36.

Similarly, 66 is triangular, A000217(11), yet not in A169911.

CROSSREFS

Cf. A000217, A169911,

Sequence in context: A025706 A025730 A066353 * A117520 A147846 A062099

Adjacent sequences:  A179650 A179651 A179652 * A179654 A179655 A179656

KEYWORD

nonn,less,base,more

AUTHOR

Jonathan Vos Post, Jul 22 2010

STATUS

approved

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Last modified August 19 04:21 EDT 2019. Contains 326109 sequences. (Running on oeis4.)