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A129630
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Numbers n such that sum of digits of n+1 is a prime.
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1
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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; refs; listen; history; internal format)
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OFFSET
| 1,2
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FORMULA
| a(n) = A028834(n) - 1.
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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);
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MATHEMATICA
| Select[Range[200], PrimeQ[Total[IntegerDigits[# + 1]]] &]
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CROSSREFS
| Sequence in context: A204660 A109133 A056077 * A026429 A086917 A004789
Adjacent sequences: A129627 A129628 A129629 * A129631 A129632 A129633
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KEYWORD
| nonn,base,easy
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AUTHOR
| Paolo P. Lava & Giorgio Balzarotti (paoloplava(AT)gmail.com), May 31 2007.
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