cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Previous Showing 11-12 of 12 results.

A060825 Smallest n-digit left truncatable prime of Henry VIII type.

Original entry on oeis.org

773, 3373, 15647, 121997, 1237547, 12184967, 126934673, 1231633967, 12181833347, 124627266947, 1213536676883, 13264242313613, 129456645661613, 1399335756373613, 12429121339693967, 198615345451813613, 1276812967623946997, 36484957213536676883, 315396334245663786197, 9918918997653319693967, 95918918997653319693967, 357686312646216567629137
Offset: 3

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Author

Lekraj Beedassy, Apr 30 2001

Keywords

Examples

			The 11-digit prime a(11) = 12181833347 is the smallest of its kind such that successive deleting of the leftmost digits produces the primes 2181833347, 181833347, 81833347, 1833347, 833347, 33347, 3347, 347, 47, 7.
		

References

  • S. Kahan and S. Weintraub, Left truncatable primes. Journal of Recreational Mathematics, vol. 29, no. 4 (1998), pp. 255-261.

Crossrefs

Extensions

a(2) removed, offset changed to 3 and a(19)-a(24) added using A055521 by Jinyuan Wang, Aug 07 2020

A173060 Partial sums of A024785.

Original entry on oeis.org

2, 5, 10, 17, 30, 47, 70, 107, 150, 197, 250, 317, 390, 473, 570, 683, 820, 987, 1160, 1357, 1580, 1863, 2176, 2493, 2830, 3177, 3530, 3897, 4270, 4653, 5050, 5493, 5960, 6483, 7030, 7643, 8260, 8903, 9550, 10203, 10876, 11559, 12302, 13075, 13872
Offset: 1

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Author

Jonathan Vos Post, Feb 08 2010

Keywords

Comments

Partial sums of left-truncatable primes. This sequence has 4260 terms. The subsequence of prime partial sums of left-truncatable primes begins 2, 5, 17, 47, 107, 197, 317, 683, 7643. The subsubsequence of left-truncatable prime partial sums of left-truncatable primes begins 2, 5, 197, 317.

Examples

			a(57) = 2 + 3 + 5 + 7 + 13 + 17 + 23 + 37 + 43 + 47 + 53 + 67 + 73 + 83 + 97 + 113 + 137 + 167 + 173 + 197 + 223 + 283 + 313 + 317 + 337 + 347 + 353 + 367 + 373 + 383 + 397 + 443 + 467 + 523 + 547 + 613 + 617 + 643 + 647 + 653 + 673 + 683 + 743 + 773 + 797 + 823 + 853 + 883 + 937 + 947 + 953 + 967 + 983 + 997 + 1223 + 1283 + 1367.
		

Crossrefs

Formula

a(n) = SUM[i=1..n] A024785(i) = SUM[i=1..n] {p prime, and every suffix of p in decimal expansion is prime, and no digits are zero}.
Previous Showing 11-12 of 12 results.