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A217919 Rows of A217916 in which 2's appear, when A217916 is formed into a number triangle. 3
1, 3, 5, 8, 10, 16, 19, 20, 23, 51, 54, 58, 70, 71, 103, 136, 139, 142, 145, 153, 161, 168, 169, 182, 204, 212, 219, 222, 224, 230, 232, 235, 240, 242, 276, 277, 286 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

The number 2 appears only in column 1 of A217916 (when treated as a triangle).

LINKS

Table of n, a(n) for n=1..37.

FORMULA

Involves triangular-indexed twin primes:

prime(a(n)*(a(n)-1)/2 + 1) - prime(a(n)*(a(n)-1)/2) = 2 for n>1 with a(1)=1.

CROSSREFS

Cf. A217916, A217918.

Sequence in context: A133097 A117176 A212987 * A127700 A101907 A242250

Adjacent sequences:  A217916 A217917 A217918 * A217920 A217921 A217922

KEYWORD

nonn

AUTHOR

Paul D. Hanna, Mar 04 2013

STATUS

approved

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Last modified October 21 20:44 EDT 2019. Contains 328315 sequences. (Running on oeis4.)