id:A129630 - OEIS Search Results

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Numbers n such that sum of digits of binomial(n,n+1) is a prime.

+0
2

1, 2, 4, 6, 10, 11, 13, 15, 19, 20, 22, 24, 28, 29, 31, 33, 37, 40, 42, 46, 48, 49, 51, 55, 57, 60, 64, 66, 69, 73, 75, 82, 84, 88, 91, 93, 97, 100, 101, 103, 105, 109, 110, 112, 114, 118, 119, 121, 123, 127, 130, 132, 136, 138, 139, 141, 145, 147, 150, 154, 156, 159 (list; graph; listen)

	OFFSET	`1,2`
	MAPLE	`P:=proc(n) local i, k, w; for i from 1 by 1 to n do w:=0; k:=binomial(i+1, i); while k>0 do w:=w+k-(trunc(k/10)*10); k:=trunc(k/10); od; if isprime(w) then print(i); fi; od; end: P(1000);`
	CROSSREFS	`Sequence in context: A089227 A109133 A056077 this_sequence A026429 A086917 A004789` `Adjacent sequences: A129627 A129628 A129629 this_sequence A129631 A129632 A129633`
	KEYWORD	`easy,nonn`
	AUTHOR	`Paolo P. Lava & Giorgio Balzarotti (ppl(AT)spl.at), May 31 2007`

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Last modified December 5 23:38 EST 2009. Contains 170428 sequences.

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