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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
OFFSET
1,2
COMMENTS
The number 2 appears only in column 1 of A217916 (when treated as a triangle).
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
Sequence in context: A133097 A117176 A212987 * A127700 A101907 A242250
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Mar 04 2013
STATUS
approved